WO2022227056A1

WO2022227056A1 - Acoustic device

Info

Publication number: WO2022227056A1
Application number: PCT/CN2021/091652
Authority: WO
Inventors: 肖乐; 郑金波; 张承乾; 廖风云; 齐心
Original assignee: 深圳市韶音科技有限公司
Priority date: 2021-04-25
Filing date: 2021-04-30
Publication date: 2022-11-03
Also published as: TW202242856A; WO2022226696A1; CN117501710A; CN115240697A

Abstract

The present application discloses an acoustic device. The acoustic device may comprise a microphone array, a processor, and at least one loudspeaker. The microphone array may be configured to pick up ambient noise. The processor may be configured to estimate a sound field of a target spatial position by using the microphone array. The target spatial position may be closer to the auditory meatus of a user than any microphone in the microphone array. The processor may be further configured to generate a noise reduction signal on the basis of the picked ambient noise and the sound field estimation of the target spatial position. The at least one loudspeaker may be configured to output a target signal according to the noise reduction signal. The target signal may be used for reducing the ambient noise. The microphone array may be provided in a target area to minimize interference signals, from the at least one loudspeaker, for the microphone array.

Description

acoustic device

cross reference

This application claims priority to International Application No. PCT/CN2021/089670, filed on April 25, 2021, the entire contents of which are incorporated herein by reference.

technical field

The present application relates to the field of acoustics, and in particular, to an acoustic device.

Background technique

The acoustic device allows users to listen to audio content and make voice calls while ensuring the privacy of user interaction content, and does not disturb surrounding people when listening. Acoustic devices can generally be divided into two categories: in-ear acoustic devices and open acoustic devices. The in-ear acoustic device may block the user's ear during use, and the user is prone to experience blockage, foreign body, swelling and pain when wearing it for a long time. The open acoustic device can open the user's ear, which is conducive to long-term wearing, but when the external noise is large, its noise reduction effect is not obvious, which reduces the user's listening experience.

Therefore, it is desirable to provide an acoustic device that can open the user's ears and improve the user's hearing experience.

SUMMARY OF THE INVENTION

One of the embodiments of the present application provides an acoustic device. The acoustic device may include a microphone array, a processor and at least one speaker. The microphone array may be configured to pick up ambient noise. The processor may be configured to estimate a sound field at a target spatial location using the microphone array. The target spatial location may be closer to the user's ear canal than any microphone in the microphone array. The processor may be further configured to generate a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location. The at least one speaker may be configured to output a target signal according to the noise reduction signal. The target signal can be used to reduce the ambient noise. The microphone array may be positioned in a target area to minimize interference signal exposure to the microphone array from the at least one loudspeaker.

In some embodiments, the generating a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location may include estimating noise at the target spatial location based on the picked-up ambient noise and based on the target The noise at the spatial location and the sound field estimate at the spatial location of the target generate the noise reduction signal.

In some embodiments, the acoustic device may further include one or more sensors for acquiring motion information of the acoustic device. The processor may be further configured to update the noise of the target spatial position and the sound field estimate of the target spatial position based on the motion information and the noise based on the updated target spatial position and the updated target The sound field estimation of the spatial location generates the noise reduction signal.

In some embodiments, the estimating noise at the target spatial location based on the picked-up ambient noise may include determining one or more spatial noise sources associated with the picked-up ambient noise and based on the spatial noise sources, Estimate the noise at the spatial location of the object.

In some embodiments, using the microphone array to estimate the sound field of the target spatial location may include constructing a virtual microphone based on the microphone array, the virtual microphone including a mathematical model or a machine learning model for representing if the The target spatial position includes audio data collected by the microphone after the microphone, and the sound field of the target spatial position is estimated based on the virtual microphone.

In some embodiments, the generating a noise reduction signal based on the picked-up ambient noise and the sound field estimation of the target spatial location may include estimating noise at the target spatial location based on the virtual microphone and estimating noise at the target spatial location based on the target spatial location The noise reduction signal is generated by an estimate of the noise and the sound field of the target spatial location.

In some embodiments, the at least one speaker may be a bone conduction speaker. The interference signal may include a sound leakage signal and a vibration signal of the bone conduction speaker. The target area may be an area where the total energy of the leakage signal and the vibration signal transmitted to the bone conduction speaker of the microphone array is the smallest.

In some embodiments, the location of the target area may be related to the orientation of the diaphragms of the microphones in the microphone array. The orientation of the diaphragm of the microphone can reduce the magnitude of the vibration signal of the bone conduction speaker received by the microphone. The diaphragm of the microphone is oriented such that the vibration signal of the bone conduction speaker received by the microphone and the sound leakage signal of the bone conduction speaker received by the microphone at least partially cancel each other. The vibration signal of the bone conduction speaker received by the microphone can reduce the sound leakage signal of the bone conduction speaker received by the microphone by 5-6 dB.

In some embodiments, the at least one speaker may be an air conduction speaker. The target area may be a minimum area of the sound pressure level of the radiated sound field of the air conduction speaker.

In some embodiments, the processor may be further configured to process the noise reduction signal based on a transfer function. The transfer function may include a first transfer function and a second transfer function. The first transfer function may represent a change in a parameter of the target signal from the at least one loudspeaker to a location where the target signal and the ambient noise cancel. The second transfer function may represent a change in a parameter of the ambient noise from the target spatial location to a location where the target signal and the ambient noise cancel. The at least one speaker may be further configured to output the target signal based on the processed noise reduction signal.

In some embodiments, the generating a noise reduction signal based on the picked-up ambient noise and the sound field estimation of the target spatial location may include dividing the picked-up ambient noise into multiple frequency bands, the multiple frequency bands corresponding to different and generating, for at least one of the plurality of frequency bands, a noise reduction signal corresponding to each of the at least one frequency band.

In some embodiments, the processor may be further configured to make amplitude and phase adjustments to noise at the target spatial location based on the sound field estimate of the target spatial location to generate the noise reduction signal.

In some embodiments, the acoustic device may further include a securing structure configured to secure the acoustic device in a position adjacent to the user's ear without blocking the user's ear canal.

In some embodiments, the acoustic device may further include a housing structure configured to carry or house the microphone array, the processor, and the at least one speaker.

One of the embodiments of the present application provides a noise reduction method. The noise reduction method may include picking up ambient noise by a microphone array. The noise reduction method may include estimating, by a processor, a sound field of a target spatial location using the microphone array. The target spatial location may be closer to the user's ear canal than any microphone in the microphone array. The noise reduction method may include generating a noise reduction signal based on the picked-up ambient noise and a sound field estimate of the target spatial location. The noise reduction method may further include outputting, by at least one speaker, a target signal according to the noise reduction signal. The target signal can be used to reduce the ambient noise. The microphone array may be positioned in a target area to minimize interference signal exposure to the microphone array from the at least one loudspeaker.

Some of the additional features of the present application may be illustrated in the following description. Some of the additional features of the present application will become apparent to those skilled in the art from a study of the following description and the corresponding drawings, or from a knowledge of the production or operation of the embodiments. The features of the present application can be implemented and obtained by practicing or using various aspects of the methods, tools and combinations set forth in the following detailed examples.

Description of drawings

The present application will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These examples are not limiting, and in these examples, the same numbers refer to the same structures, wherein:

FIG. 1 is a schematic structural diagram of an exemplary acoustic device according to some embodiments of the present application;

FIG. 2 is a schematic structural diagram of an exemplary processor according to some embodiments of the present application;

3 is an exemplary noise reduction flowchart of an acoustic device according to some embodiments of the present application;

FIG. 4 is an exemplary noise reduction flowchart of an acoustic device according to some embodiments of the present application;

5A-D are schematic diagrams of exemplary arrangements of microphone arrays according to some embodiments of the present application;

6A-B are schematic diagrams of exemplary arrangements of microphone arrays according to some embodiments of the present application;

FIG. 7 is an exemplary flowchart of estimating noise at a spatial location of a target according to some embodiments of the present application;

FIG. 8 is a schematic diagram of estimating noise at a spatial position of a target according to some embodiments of the present application;

FIG. 9 is an exemplary flowchart of estimating the sound field and noise of a target spatial position according to some embodiments of the present application;

10 is a schematic diagram of constructing a virtual microphone according to some embodiments of the present application;

FIG. 11 is a schematic diagram of the sound leakage signal distribution of the three-dimensional sound field at 1000 Hz of the bone conduction speaker according to some embodiments of the present application;

FIG. 12 is a schematic diagram illustrating the distribution of sound leakage signals in a two-dimensional sound field at 1000 Hz of a bone conduction speaker according to some embodiments of the present application;

13 is a schematic diagram of the frequency response of the total signal of the vibration signal and the sound leakage signal of the bone conduction speaker according to some embodiments of the present application;

14A-B are schematic diagrams of sound field distribution of an air conduction speaker according to some embodiments of the present application;

FIG. 15 is an exemplary flowchart of outputting a target signal based on a transfer function according to some embodiments of the present application; and

FIG. 16 is an exemplary flowchart of estimating noise at a spatial location of a target according to some embodiments of the present application.

Detailed ways

In order to illustrate the technical solutions of the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings that are used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without any creative effort, the present application can also be applied to the present application according to these drawings. other similar situations. Unless obvious from the locale or otherwise specified, the same reference numbers in the figures represent the same structure or operation.

It should be understood that "system", "device", "unit" and/or "module" as used herein is a method used to distinguish different components, elements, parts, parts or assemblies at different levels. However, other words may be replaced by other expressions if they serve the same purpose.

As shown in this application and in the claims, unless the context clearly dictates otherwise, the words "a", "an", "an" and/or "the" are not intended to be specific in the singular and may include the plural. Generally speaking, the terms "comprising" and "comprising" only imply that the clearly identified steps and elements are included, and these steps and elements do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

Flow diagrams are used in this application to illustrate operations performed by a system according to an embodiment of the application. It should be understood that the preceding or following operations are not necessarily performed in the exact order. Instead, the various steps can be processed in reverse order or simultaneously. At the same time, other actions can be added to these procedures, or a step or steps can be removed from these procedures.

An open acoustic device, such as an open acoustic earphone, is an acoustic device that can open a user's ear. The open acoustic device can fix the speaker at a position near the user's ear without blocking the user's ear canal through a fixing structure (eg, ear hook, head hook, glasses leg, etc.). When the user uses the open acoustic device, the external environment noise can also be heard by the user, which makes the user's hearing experience poor. For example, in places with high ambient noise (eg, streets, scenic spots, etc.), when a user uses an open acoustic device to play music, the noise from the external environment will directly enter the user's ear canal, so that the user can hear the louder environment. Noise, ambient noise can interfere with the user's music listening experience. For another example, when a user wears an open acoustic device to make a call, the microphone not only picks up the user's own speaking voice, but also picks up ambient noise, which makes the user's call experience poor.

Based on the above problems, an acoustic device is provided in the embodiments of the present application. The acoustic device may include a microphone array, a processor, and at least one speaker. The microphone array can be configured to pick up ambient noise. The processor may be configured to estimate the sound field of the target spatial location using the microphone array. The target spatial location may be closer to the user's ear canal than any microphone in the microphone array. It can be understood that each microphone in the microphone array may be distributed in different positions near the user's ear canal, and each microphone in the microphone array is used to estimate the sound field near the user's ear canal position (eg, a target spatial position). The processor may be further configured to generate a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location. The at least one speaker may be configured to output the target signal according to the noise reduction signal. The target signal can be used to reduce ambient noise. Additionally, the microphone array may be positioned in the target area to minimize the microphone array's exposure to interfering signals from the at least one loudspeaker. When at least one speaker is a bone conduction speaker, the interference signal may include a leakage signal and a vibration signal of the bone conduction speaker, and the target area may be an area where the total energy of the leakage signal and vibration signal of the bone conduction speaker transmitted to the microphone array is the smallest . When the at least one loudspeaker is an air-conducting loudspeaker, the target area may be an area of minimum sound pressure level of the radiated sound field of the air-conducting loudspeaker.

In the embodiments of the present application, the target signal output by at least one speaker is used to reduce the ambient noise at the user's ear canal (for example, the target spatial position) through the above setting, so as to realize the active noise reduction of the acoustic device, and improve the user's performance when using the device. Aural experience during acoustic installation.

Further, in the embodiment of the present application, the microphone array (also referred to as a feedforward microphone) can simultaneously realize the pickup of ambient noise and the estimation of the sound field at the user's ear canal (eg, the target spatial position).

In addition, in the embodiment of the present application, the microphone array is arranged in the target area, which reduces or prevents the microphone array from picking up the interference signal (for example, the target signal) emitted by at least one speaker, thereby ensuring the active noise reduction of the open acoustic device. accomplish.

FIG. 1 is a schematic structural diagram of an exemplary acoustic device 100 according to some embodiments of the present application. In some embodiments, the acoustic device 100 may be an open acoustic device. As shown in FIG. 1 , the acoustic device 100 may include a microphone array 110 , a processor 120 and a speaker 130 . In some embodiments, the microphone array 110 can pick up ambient noise, and convert the picked-up ambient noise into electrical signals and transmit them to the processor 120 for processing. The processor 120 may couple (eg, electrically connect) the microphone array 110 and the speaker 130 . The processor 120 may receive and process the electrical signals communicated by the microphone array 110 to generate a noise reduction signal and communicate the generated noise reduction signal to the speaker 130 . The speaker 130 may output the target signal according to the noise reduction signal. The target signal can be used to reduce or cancel the ambient noise at the user's ear canal position (eg, the target spatial position), so as to realize active noise reduction of the acoustic device 100 and improve the user's listening experience during the use of the acoustic device 100 .

The microphone array 110 may be configured to pick up ambient noise. In some embodiments, ambient noise may refer to a combination of various external sounds in the environment in which the user is located. For example only, ambient noise may include one or more of traffic noise, industrial noise, building construction noise, social noise, and the like. Traffic noise may include, but is not limited to, driving noise of motor vehicles, whistle noise, and the like. Industrial noise may include, but is not limited to, factory power machinery operating noise, and the like. Building construction noise may include, but is not limited to, power machinery excavation noise, hole drilling noise, stirring noise, and the like. Social living environment noise may include, but is not limited to, crowd assembly noise, entertainment and publicity noise, crowd noise, household appliance noise, and the like. In some embodiments, the microphone array 110 may be disposed near the user's ear canal to pick up the ambient noise transmitted to the user's ear canal, and convert the picked-up ambient noise into electrical signals and transmit them to the processor 120 for processing. In some embodiments, the microphone array 110 may be positioned at the user's left and/or right ear. For example, the microphone array 110 may include a first sub-microphone array and a second sub-microphone array. The first sub-microphone array may be located at the user's left ear, and the second sub-microphone array may be located at the user's right ear. The first sub-microphone array and the second sub-microphone array may enter the working state at the same time or one of the two may enter the working state.

In some embodiments, the ambient noise may include the sound of the user speaking. For example, the microphone array 110 may pick up ambient noise according to the talking state of the acoustic device 100 . When the acoustic device 100 is not in a call state, the sound produced by the user's own speech can be regarded as environmental noise, and the microphone array 110 can simultaneously pick up the user's own speech and other environmental noises. When the acoustic device 100 is in a call state, the sound produced by the user's own speech may not be regarded as ambient noise, and the microphone array 110 may pick up ambient noise in addition to the user's own speaking sound. For example, the microphone array 110 may pick up noise emanating from a noise source located a certain distance (eg, 0.5 meters, 1 meter) away from the microphone array 110 .

In some embodiments, the microphone array 110 may include one or more air conduction microphones. For example, when a user listens to music using the acoustic device 100, the air conduction microphone can simultaneously acquire the noise of the external environment and the voice of the user when speaking, and use the acquired noise of the external environment and the voice of the user as the ambient noise. In some embodiments, the microphone array 110 may also include one or more bone conduction microphones. The bone conduction microphone can directly contact the user's skin, and the vibration signal generated by the bones or muscles when the user speaks can be directly transmitted to the bone conduction microphone, and then the bone conduction microphone converts the vibration signal into an electrical signal, and transmits the electrical signal to the processor 120 to be processed. The bone conduction microphone may also not be in direct contact with the human body, and the vibration signal generated by the bones or muscles when the user speaks can be first transmitted to the casing structure of the acoustic device 100, and then transmitted to the bone conduction microphone by the casing structure. In some embodiments, when the user is in a call state, the processor 120 may use the sound signal collected by the air conduction microphone as environmental noise and use the environmental noise for noise reduction, and the sound signal collected by the bone conduction microphone may be transmitted to the terminal device as a voice signal , so as to ensure the call quality of the user during the call.

In some embodiments, the processor 120 may control the switch states of the bone conduction microphone and the air conduction microphone based on the working state of the acoustic device 100 . The working state of the acoustic device 100 may refer to the usage state used when the user wears the acoustic device 100 . Just as an example, the working state of the acoustic device 100 may include, but is not limited to, a talking state, a non-calling state (eg, a music playing state), a voice message sending state, and the like. In some embodiments, when the microphone array 110 picks up ambient noise, the on/off state of the bone conduction microphone and the on/off state of the air conduction microphone in the microphone array 110 may be determined according to the working state of the acoustic device 100 . For example, when the user wears the acoustic device 100 to play music, the switch state of the bone conduction microphone may be the standby state, and the switch state of the air conduction microphone may be the working state. For another example, when the user wears the acoustic device 100 to send a voice message, the switch state of the bone conduction microphone may be the working state, and the switch state of the air conduction microphone may be the working state. In some embodiments, the processor 120 may control the on/off state of the microphones (eg, bone conduction microphones, air conduction microphones) in the microphone array 110 by sending a control signal.

In some embodiments, when the working state of the acoustic device 100 is a non-calling state (eg, a music playing state), the processor 120 may control the bone conduction microphone to be in a standby state and the air conduction microphone to be in a working state. When the acoustic device 100 is not in a call state, the sound signal of the user speaking by himself may be regarded as environmental noise. In this case, the voice signal of the user's own speaking included in the ambient noise picked up by the air conduction microphone may not be filtered out, so that the voice signal of the user's own voice, as a part of the ambient noise, may also be similar to the target signal output by the speaker 130 . offset. When the working state of the acoustic device 100 is the talking state, the processor 120 may control the bone conduction microphone to be in the working state and the air conduction microphone to be in the working state. When the acoustic device 100 is in a call state, the voice signal of the user's own speech needs to be retained. In this case, the processor 120 may send a control signal to control the bone conduction microphone to be in a working state, the bone conduction microphone picks up the sound signal of the user speaking, and the processor 120 removes the user speaking picked up by the bone conduction microphone from the ambient noise picked up by the air conduction microphone So that the voice signal of the user's own speech does not cancel the target signal output by the speaker 130, so as to ensure the normal call state of the user.

In some embodiments, when the working state of the acoustic device 100 is the talking state, if the sound pressure of the ambient noise is greater than the preset threshold, the processor 120 may control the bone conduction microphone to maintain the working state. The sound pressure of ambient noise can reflect the intensity of ambient noise. The preset threshold here may be a value pre-stored in the acoustic device 100, for example, any other value such as 50dB, 60dB, or 70dB. When the sound pressure of the ambient noise is greater than the preset threshold, the ambient noise will affect the call quality of the user. The processor 120 can control the bone conduction microphone to maintain a working state by sending a control signal, and the bone conduction microphone can acquire the vibration signal of the facial muscles of the user when speaking, without basically picking up external environmental noise. At this time, the vibration signal picked up by the bone conduction microphone is used. As a voice signal during a call, so as to ensure the normal call of the user.

In some embodiments, when the working state of the acoustic device 100 is the talking state, if the sound pressure of the ambient noise is lower than the preset threshold, the processor 120 may control the bone conduction microphone to switch from the working state to the standby state. When the sound pressure of the environmental noise is less than the preset threshold, the sound pressure of the environmental noise is smaller than the sound pressure of the sound signal generated by the user's speech, and the sound generated by the user's speech transmitted to a certain position of the user's ear through the first sound path After the signal is partially offset by the target signal output by the speaker 130 and transmitted to a certain position of the user's ear through the second sound path, the remaining sound signal generated by the user's speech can still be received by the user's auditory center, which is sufficient to ensure the user's normal conversation. In this case, the processor 120 can control the bone conduction microphone to switch from the working state to the standby state by sending a control signal, thereby reducing the complexity of signal processing and the power consumption of the acoustic device 100 .

In some embodiments, the microphone array 110 may include dynamic microphones, ribbon microphones, condenser microphones, electret microphones, electromagnetic microphones, carbon microphones, etc., or any combination thereof, according to the working principle of the microphones. In some embodiments, the arrangement of the microphone array 110 may include a linear array (eg, linear, curved), a planar array (eg, cross, circle, ring, polygon, mesh, etc., regular and/or irregular shapes), stereoscopic arrays (eg, cylindrical, spherical, hemispherical, polyhedral, etc.), etc., or any combination thereof. For more introduction on the arrangement of the microphone array 110, reference may be made to other places in this application, for example, FIGS. 5A-D, 6A-B and their corresponding descriptions.

The processor 120 may be configured to use the microphone array 110 to estimate the sound field of the target spatial location. The sound field of a target spatial location may refer to the distribution and variation of sound waves at or near the target spatial location (eg, as a function of time, as a function of location). The physical quantities describing the sound field may include sound pressure, sound frequency, sound amplitude, sound phase, sound source vibration velocity, or medium (eg air) density, and the like. In general, these physical quantities can be functions of position and time. The target spatial location may refer to a spatial location close to the user's ear canal by a specific distance. The target spatial location may be closer to the user's ear canal than any microphone in the microphone array 110 . The specific distance here may be a fixed distance, for example, 0.5 cm, 1 cm, 2 cm, 3 cm, and the like. In some embodiments, the target spatial position may be related to the number of each microphone in the microphone array 110 and the distribution position relative to the user's ear canal. The target spatial position can be adjusted by adjusting the number of the microphones in the microphone array 110 and/or the distribution position relative to the user's ear canal. For example, by increasing the number of microphones in the microphone array 110, the target spatial location can be brought closer to the user's ear canal. For another example, the target spatial position can also be made closer to the user's ear canal by reducing the distance between the microphones in the microphone array 110 . For another example, the arrangement of the microphones in the microphone array 110 can also be changed to make the target spatial position closer to the user's ear canal.

The processor 120 may be further configured to generate a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location. Specifically, the processor 120 may receive and process the ambient noise-converted electrical signal transmitted by the microphone array 110 to obtain parameters (eg, amplitude, phase, etc.) of the ambient noise. The processor 120 may further adjust parameters of the ambient noise (eg, amplitude, phase, etc.) based on the sound field estimate of the target spatial location to generate a noise reduction signal. The parameters of the noise reduction signal (eg, amplitude, phase, etc.) correspond to parameters of the ambient noise. For example only, the amplitude of the noise reduction signal may be approximately equal to the amplitude of the ambient noise, and the phase of the noise reduction signal may be approximately opposite to the phase of the ambient noise. In some embodiments, the processor 120 may include hardware modules and software modules. Just as an example, the hardware module may include a digital signal processing (Digital Signal Processor, DSP) chip, an advanced reduced instruction set machine (Advanced RISC Machines, ARM), and the software module may include an algorithm module. For more information on processor 120, reference may be made elsewhere in this application, eg, FIG. 2 and its corresponding description.

The speaker 130 may be configured to output the target signal according to the noise reduction signal. The target signal may be used to reduce or cancel ambient noise delivered to a certain location of the user's ear (eg, tympanic membrane, basilar membrane). In some embodiments, when the user wears the acoustic device 100, the speaker 130 may be located near the user's ear. In some embodiments, depending on the working principle of the speaker, the speaker 130 may include a dynamic speaker (eg, a moving coil speaker), a magnetic speaker, an ion speaker, an electrostatic speaker (or a condenser speaker), a piezoelectric speaker, etc. one or more of. In some embodiments, the speaker 130 may include an air conduction speaker and/or a bone conduction speaker depending on how the sound output by the speaker propagates. In some embodiments, the number of speakers 130 may be one or more. When the number of speakers 130 is one, the speaker 130 can be used to output the target signal to eliminate ambient noise and can be used to deliver the sound information (eg, device media audio, call far-end audio) to the user that the user needs to hear. For example, when the number of speakers 130 is one and is an air conduction speaker, the air conduction speaker can be used to output a target signal to cancel ambient noise. In this case, the target signal may be a sound wave (ie, vibration of air), which may be transmitted through the air to the target spatial location and cancel each other with ambient noise at the target spatial location. At the same time, the air conduction speaker can also be used to transmit the sound information that the user needs to hear to the user. For another example, when the number of speakers 130 is one and it is a bone conduction speaker, the bone conduction speaker can be used to output the target signal to eliminate ambient noise. In this case, the target signal may be a vibration signal (eg, vibration of a speaker housing) that may be transmitted through bone or tissue to the user's basilar membrane and cancels out ambient noise at the user's basilar membrane. At the same time, the bone conduction speaker can also be used to transmit the sound information that the user needs to hear to the user. When the number of speakers 130 is multiple, a part of the multiple speakers 130 can be used to output the target signal to eliminate ambient noise, and the other part can be used to transmit the sound information that the user needs to listen to (for example, device media audio, call far-end audio). For example, when the number of speakers 130 is multiple and includes bone conduction speakers and air conduction speakers, the air conduction speakers can be used to output sound waves to reduce or eliminate ambient noise, and the bone conduction speakers can be used to transmit the sound information that the user needs to hear to the user . Compared with air conduction speakers, bone conduction speakers can directly transmit mechanical vibrations through the user's body (eg, bones, skin tissue, etc.) to the user's auditory nerves, and the interference to the air conduction microphones that pick up ambient noise is relatively high during this process. Small.

It should be noted that the speaker 130 may be an independent functional device, or may be part of a single device capable of implementing multiple functions. For example only, the speaker 130 may be integrated and/or formed in one piece with the processor 120 . In some embodiments, when the number of speakers 130 is multiple, the arrangement of the multiple speakers 130 may include linear arrays (eg, straight, curved), planar arrays (eg, cross, mesh, circular, annular, polygonal and other regular and/or irregular shapes), three-dimensional arrays (eg, cylindrical, spherical, hemispherical, polyhedron, etc.), etc., or any combination thereof, which is not limited herein. In some embodiments, the speaker 130 may be positioned at the user's left and/or right ear. For example, the speaker 130 may include a first sub-speaker and a second sub-speaker. The first sub-speaker may be located at the user's left ear, and the second sub-speaker may be located at the user's right ear. The first sub-speaker and the second sub-speaker may enter the working state at the same time or one of the two may enter the working state. In some embodiments, the speaker 130 may be a speaker with a directional sound field, the main lobe of which is directed to the user's ear canal.

In some embodiments, the acoustic device 100 may also include one or more sensors 140 . One or more sensors 140 may be electrically connected to other components of acoustic device 100 (eg, processor 120). One or more sensors 140 may be used to obtain physical location and/or motion information of the acoustic device 100. For example only, the one or more sensors 140 may include an Inertial Measurement Unit (IMU), a Global Positioning System (GPS), a radar, and the like. The motion information may include motion trajectory, motion direction, motion speed, motion acceleration, motion angular velocity, motion-related time information (eg, motion start time, end time), etc., or any combination thereof. Taking an IMU as an example, the IMU may include a Microelectro Mechanical System (MEMS). The microelectromechanical system may include multi-axis accelerometers, gyroscopes, magnetometers, etc., or any combination thereof. The IMU may be used to detect the physical location and/or motion information of the acoustic device 100 to enable control of the acoustic device 100 based on the physical location and/or motion information. More information on the control of the acoustic device 100 based on physical location and/or motion information can be found elsewhere in this application, eg, FIG. 4 and its corresponding description.

In some embodiments, the acoustic device 100 may include a signal transceiver 150 . The signal transceiver 150 may be electrically connected with other components of the acoustic device 100 (eg, the processor 120). In some embodiments, the signal transceiver 150 may include Bluetooth, an antenna, and the like. The acoustic device 100 may communicate with other external devices (eg, mobile phones, tablet computers, smart watches) through the signal transceiver 150 . For example, the acoustic device 100 may wirelessly communicate with other devices via Bluetooth.

In some embodiments, the acoustic device 100 may include a housing structure 160 . Housing structure 160 may be configured to carry other components of acoustic device 100 (eg, microphone array 110, processor 120, speaker 130, one or more sensors 140, signal transceiver 150). In some embodiments, the housing structure 160 may be a closed or semi-closed structure with a hollow interior, and the other components of the acoustic device 100 are located in or on the housing structure. In some embodiments, the shape of the shell structure may be a regular or irregular three-dimensional structure such as a rectangular parallelepiped, a cylinder, and a truncated cone. When the user wears the acoustic device 100, the housing structure may be located close to the user's ear. For example, the housing structure may be located on the peripheral side (eg, the front side or the back side) of the user's pinna. As another example, the housing structure may be located on the user's ear without blocking or covering the user's ear canal. In some embodiments, the acoustic device 100 may be a bone conduction earphone, and at least one side of the housing structure may be in contact with the user's skin. Acoustic drivers (eg, vibrating speakers) in bone conduction headphones convert audio signals into mechanical vibrations that can be transmitted to the user's auditory nerves through the housing structure and the user's bones. In some embodiments, the acoustic device 100 may be an air conduction earphone, and at least one side of the housing structure may or may not be in contact with the user's skin. The side wall of the housing structure includes at least one sound guide hole, and the speaker in the air conduction earphone converts the audio signal into the air conduction sound, and the air conduction sound can be radiated toward the user's ear through the sound guide hole.

In some embodiments, the acoustic device 100 may include a fixed structure 170 . The securing structure 170 may be configured to secure the acoustic device 100 in a position near the user's ear and without blocking the user's ear canal. In some embodiments, the securing structure 170 may be physically connected (eg, snapped, screwed, etc.) with the housing structure 160 of the acoustic device 100 . In some embodiments, the housing structure 160 of the acoustic device 100 may be part of the fixed structure 170 . In some embodiments, the fixing structure 170 may include ear hooks, back hooks, elastic bands, temples, etc., so that the acoustic device 100 can be better fixed near the user's ears and prevent the user from falling during use. For example, the securing structure 170 may be an ear loop, which may be configured to be worn around the ear area. In some embodiments, the earhook can be a continuous hook and can be elastically stretched to fit on the user's ear, while the earhook can also apply pressure to the user's pinna, so that the acoustic device 100 is securely attached Fixed to a specific location on the user's ear or head. In some embodiments, the earhook may be a discontinuous band. For example, an earhook may include a rigid portion and a flexible portion. The rigid part may be made of rigid material (eg, plastic or metal), and the rigid part may be fixed to the housing structure 160 of the acoustic device 100 by means of a physical connection (eg, snap-fit, screw connection, etc.). The flexible portion may be made of elastic material (eg, cloth, composite or/and neoprene). As another example, the securing structure 170 may be a neckband configured to be worn around the neck/shoulder area. For another example, the fixing structure 170 may be an eyeglass leg, which, as a part of the eyeglasses, is erected on the user's ear.

In some embodiments, the acoustic device 100 may further include an interaction module (not shown) for adjusting the sound pressure of the target signal. In some embodiments, the interaction module may include buttons, voice assistants, gesture sensors, and the like. The user can adjust the noise reduction mode of the acoustic device 100 by controlling the interaction module. Specifically, the user can adjust (eg, amplify or reduce) the amplitude information of the noise reduction signal by controlling the interaction module, so as to change the sound pressure of the target signal emitted by the speaker array 130, thereby achieving different noise reduction effects. For example only, the noise reduction mode may include a strong noise reduction mode, a medium noise reduction mode, a weak noise reduction mode, and the like. For example, when the user wears the acoustic device 100 indoors, the external environment noise is small, and the user can turn off or adjust the noise reduction mode of the acoustic device 100 to a weak noise reduction mode through the interaction module. For another example, when the user wears the acoustic device 100 when walking in public places such as the street, the user needs to maintain a certain ability to perceive the surrounding environment while listening to audio signals (eg, music, voice information) to cope with emergencies, At this time, the user can select the intermediate noise reduction mode through the interaction module (for example, a button or a voice assistant) to preserve the surrounding ambient noise (such as sirens, impacts, car horns, etc.). For another example, when a user takes a subway or a plane, the user can select a strong noise reduction mode through the interaction module to further reduce ambient noise. In some embodiments, the processor 120 may also send prompt information to the acoustic apparatus 100 or a terminal device (eg, a mobile phone, a smart watch, etc.) that is communicatively connected to the acoustic apparatus 100 based on the ambient noise intensity range, so as to remind the user to adjust the noise reduction mode .

It should be noted that the above description with respect to FIG. 1 is provided for illustrative purposes only and is not intended to limit the scope of the present application. Numerous changes and modifications may be made by those of ordinary skill in the art in light of the teachings of this application. In some embodiments, one or more components in acoustic device 100 (eg, one or more sensors 140, signal transceivers 150, fixed structures 170, interaction modules, etc.) may be omitted. In some embodiments, one or more components of acoustic device 100 may be replaced by other elements that perform similar functions. For example, the acoustic device 100 may not include the fixed structure 170, and the housing structure 160 or a portion thereof may have a human ear-compatible shape (eg, circular, oval, polygonal (regular or irregular), U-shaped, V-shaped, semi-circular) shell structure so that the shell structure can hang near the user's ear. In some embodiments, a component in acoustic device 100 may be split into multiple sub-components, or multiple components may be combined into a single component. These changes and modifications do not depart from the scope of this application.

FIG. 2 is a schematic structural diagram of an exemplary processor 120 according to some embodiments of the present application. As shown in FIG. 2 , the processor 120 may include an analog-to-digital conversion unit 210 , a noise estimation unit 220 , an amplitude-phase compensation unit 230 and a digital-to-analog conversion unit 240 .

In some embodiments, the analog-to-digital conversion unit 210 may be configured to convert the signal input by the microphone array 110 into a digital signal. Specifically, the microphone array 110 picks up the environmental noise, and converts the picked-up environmental noise into electrical signals and transmits them to the processor 120 . After receiving the electrical signal of environmental noise sent by the microphone array 110, the analog-to-digital conversion unit 210 may convert the electrical signal into a digital signal. In some embodiments, the analog-to-digital conversion unit 210 may be electrically connected to the microphone array 110 and further to other components of the processor 120 (eg, the noise estimation unit 220). Further, the analog-to-digital conversion unit 210 may transfer the converted digital signal of environmental noise to the noise estimation unit 220 .

In some embodiments, the noise estimation unit 220 may be configured to estimate the ambient noise from the received digital signal of the ambient noise. For example, the noise estimation unit 220 may estimate the relevant parameters of the environmental noise at the target spatial location according to the received digital signal of the environmental noise. For example only, the parameters may include a noise source (eg, location, orientation), transfer direction, magnitude, phase, etc., of the noise at the target spatial location, or any combination thereof. In some embodiments, the noise estimation unit 220 may also be configured to use the microphone array 110 to estimate the sound field of the target spatial location. For more information on estimating the sound field of the target spatial location, reference can be made elsewhere in this application, eg, FIG. 4 and its corresponding description. In some embodiments, the noise estimation unit 220 may be electrically connected with other components of the processor 120 (eg, the amplitude and phase compensation unit 230). Further, the noise estimation unit 220 may transfer the estimated parameters related to environmental noise and the sound field of the target spatial position to the amplitude and phase compensation unit 230 .

In some embodiments, the amplitude and phase compensation unit 230 may be configured to compensate the estimated ambient noise related parameters according to the sound field of the target spatial location. For example, the amplitude and phase compensation unit 230 may compensate the amplitude and phase of the ambient noise according to the sound field of the target spatial position to obtain a digital noise reduction signal. In some embodiments, the amplitude and phase compensation unit 230 may adjust the amplitude of the ambient noise and inversely compensate the phase of the ambient noise to obtain a digital noise reduction signal. The amplitude of the digital noise reduction signal may be approximately equal to the amplitude of the digital signal corresponding to the environmental noise, and the phase of the digital noise reduction signal may be approximately opposite to the phase of the digital signal corresponding to the environmental noise. In some embodiments, the amplitude and phase compensation unit 230 may be electrically connected with other components of the processor 120 (eg, the digital-to-analog conversion unit 240 ). Further, the amplitude and phase compensation unit 230 may transmit the digital noise reduction signal to the digital-to-analog conversion unit 240 .

In some embodiments, the digital-to-analog conversion unit 240 may be configured to convert the digital noise reduction signal to an analog signal to obtain a noise reduction signal (eg, an electrical signal). For example only, the digital-to-analog conversion unit 240 may include pulse width modulation (Pulse Width Modulation, PMW). In some embodiments, the digital-to-analog conversion unit 240 may be electrically connected with other components of the processor 120 (eg, the speaker 130). Further, the digital-to-analog conversion unit 240 may transmit the noise reduction signal to the speaker 130 .

In some embodiments, the processor 120 may include a signal amplification unit 250 . The signal amplifying unit 250 may be configured to amplify the input signal. For example, the signal amplifying unit 250 may amplify the signal input by the microphone array 110 . Just as an example, when the acoustic device 100 is in a call state, the signal amplification unit 250 may be used to amplify the voice of the user input by the microphone array 110 . For another example, the signal amplifying unit 250 may amplify the amplitude of the ambient noise according to the sound field of the target spatial position. In some embodiments, the signal amplification unit 250 may be electrically connected with other components of the processor 120 (eg, the microphone array 110, the noise estimation unit 220, the amplitude and phase compensation unit 230).

It should be noted that the above description with respect to FIG. 2 is provided for illustrative purposes only and is not intended to limit the scope of the present application. Numerous changes and modifications may be made by those of ordinary skill in the art in light of the teachings of this application. In some embodiments, one or more components in processor 120 (eg, signal amplification unit 250) may be omitted. In some embodiments, a component in processor 120 may be split into multiple sub-components, or multiple components may be combined into a single component. For example, the noise estimation unit 220 and the amplitude and phase compensation unit 230 may be integrated into one component for realizing the functions of the noise estimation unit 220 and the amplitude and phase compensation unit 230 . These changes and modifications do not depart from the scope of this application.

3 is an exemplary noise reduction flow diagram of an acoustic device according to some embodiments of the present application. In some embodiments, process 300 may be performed by acoustic device 100 . As shown in FIG. 3, the process 300 may include:

In step 310, ambient noise is picked up. In some embodiments, this step may be performed by microphone array 110 .

According to the related description in FIG. 1 , ambient noise may refer to a combination of various external sounds (eg, traffic noise, industrial noise, building construction noise, social noise) in the environment where the user is located. In some embodiments, the microphone array 110 may be located near the user's ear canal for picking up ambient noise delivered to the user's ear canal. Further, the microphone array 110 can convert the picked-up ambient noise signal into an electrical signal and transmit it to the processor 120 for processing.

In step 320, the noise of the target spatial location is estimated based on the picked-up ambient noise. In some embodiments, this step may be performed by processor 120 .

In some embodiments, the processor 120 may perform signal separation on the picked-up ambient noise. In some embodiments, the ambient noise picked up by the microphone array 110 may include various sounds. The processor 120 may perform signal analysis on the ambient noise picked up by the microphone array 110 to separate the various sounds. Specifically, the processor 120 can adaptively adjust the parameters of the filter according to the statistical distribution characteristics and structural characteristics of various sounds in different dimensions such as space, time domain, and frequency domain, and estimate the parameter information of each sound signal in the environmental noise, And complete the signal separation process according to the parameter information of each sound signal. In some embodiments, the statistical distribution characteristics of noise may include probability distribution density, power spectral density, autocorrelation function, probability density function, variance, mathematical expectation, and the like. In some embodiments, the structured features of noise may include noise distribution, noise intensity, global noise intensity, noise rate, etc., or any combination thereof. The global noise intensity may refer to an average noise intensity or a weighted average noise intensity. The noise rate may refer to the degree of dispersion of the noise distribution. For example only, the ambient noise picked up by the microphone array 110 may include a first signal, a second signal, and a third signal. The processor 120 obtains the differences between the first signal, the second signal, and the third signal in the space (eg, where the signals are located), the time domain (eg, delay), and the frequency domain (eg, amplitude, phase), and according to the three The first signal, the second signal, and the third signal are separated by the difference in these dimensions, and the relatively pure first signal, the second signal, and the third signal are obtained. Further, the processor 120 may update the ambient noise according to the parameter information (eg, frequency information, phase information, amplitude information) of the separated signal. For example, the processor 120 may determine that the first signal is the user's call sound according to the parameter information of the first signal, and remove the first signal from the ambient noise to update the ambient noise. In some embodiments, the removed first signal may be transmitted to the far end of the call. For example, when the user wears the acoustic device 100 for a voice call, the first signal may be transmitted to the far end of the call.

The target spatial location is based on a location determined by the microphone array 110 at or near the user's ear canal. According to the related description in FIG. 1 , the target spatial position may refer to a spatial position close to a user's ear canal (eg, ear canal) at a specific distance (eg, 0.5 cm, 1 cm, 2 cm, 3 cm). In some embodiments, the target spatial location is closer to the user's ear canal than any of the microphones in the microphone array 110 . According to the relevant description in FIG. 1 , the target spatial position is related to the number of microphones in the microphone array 110 and the distribution position relative to the user’s ear canal. By adjusting the number of microphones in the microphone array 110 and/or relative to the user’s ear canal The distribution position can be adjusted to the target spatial position. In some embodiments, estimating noise at the spatial location of the target based on the picked-up environmental noise (or updated environmental noise) may further include determining one or more spatial noise sources related to the picked-up environmental noise, estimating the target based on the spatial noise sources Noise in spatial location. The ambient noise picked up by the microphone array 110 may come from different azimuths and different types of spatial noise sources. The parameter information (eg, frequency information, phase information, and amplitude information) corresponding to each spatial noise source is different. In some embodiments, the processor 120 may perform signal separation and extraction on the noise at the target spatial location according to the statistical distribution and structural features of different types of noise in different dimensions (eg, spatial domain, time domain, frequency domain, etc.), so as to obtain Noise of different types (eg, different frequencies, different phases, etc.), and estimate the parameter information (eg, amplitude information, phase information, etc.) corresponding to each noise. In some embodiments, the processor 120 may further determine the overall parameter information of the noise at the target spatial position according to the parameter information corresponding to different types of noise at the target spatial position. For more information on estimating noise at a target spatial location based on one or more spatial noise sources, reference may be made elsewhere in the specification of this application, eg, FIGS. 7-8 and their corresponding descriptions.

In some embodiments, estimating the noise at the target spatial location based on the picked-up ambient noise (or updated ambient noise) may further include constructing a virtual microphone based on the microphone array 110 and estimating the noise at the target spatial location based on the virtual microphone. For more content about estimating noise at the spatial location of the target based on the virtual microphone, reference may be made to other places in the specification of this application, such as FIGS. 9-10 and their corresponding descriptions.

In step 330, a noise reduction signal is generated based on the noise at the target spatial location. In some embodiments, this step may be performed by processor 120 .

In some embodiments, the processor 120 may generate a noise reduction signal based on the parameter information (eg, amplitude information, phase information, etc.) of the noise at the target spatial location obtained in step 320 . In some embodiments, the phase difference between the phase of the noise reduction signal and the phase of the noise at the target spatial location may be less than or equal to a preset phase threshold. The preset phase threshold may be in the range of 90-180 degrees. The preset phase threshold can be adjusted within this range according to user needs. For example, when the user does not want to be disturbed by the sound of the surrounding environment, the preset phase threshold may be a larger value, such as 180 degrees, that is, the phase of the noise reduction signal is opposite to the phase of the noise at the target spatial position. For another example, when the user wants to be sensitive to the surrounding environment, the preset phase threshold may be a small value, such as 90 degrees. It should be noted that the more ambient sounds the user wishes to receive, the closer the preset phase threshold may be to 90 degrees, and the less ambient sounds the user wishes to receive, the closer the preset phase threshold may be to 180 degrees. In some embodiments, when the phase of the noise reduction signal is a certain phase (eg, the phase is opposite) to the noise at the target spatial position, the amplitude of the noise at the target spatial position is different from the amplitude of the noise reduction signal. Can be less than or equal to the preset amplitude threshold. For example, when the user does not want to be disturbed by the sound of the surrounding environment, the preset amplitude threshold may be a small value, such as 0 dB, that is, the amplitude of the noise reduction signal is equal to the amplitude of the noise at the target spatial position. For another example, when the user wishes to remain sensitive to the surrounding environment, the preset amplitude threshold may be a relatively large value, for example, approximately equal to the amplitude of the noise at the target spatial position. It should be noted that the more the user wishes to receive the sound of the surrounding environment, the closer the preset amplitude threshold can be to the amplitude of the noise at the target spatial position, and the less the user wishes to receive the sound of the surrounding environment, the preset amplitude threshold can be The closer it is to 0dB.

In some embodiments, the speaker 130 may output the target signal based on the noise reduction signal generated by the processor 120 . For example, the speaker 130 may convert a noise reduction signal (eg, an electrical signal) into a target signal (ie, a vibration signal) based on a vibration component in the speaker 130, and the target signal may cancel out the ambient noise. In some embodiments, when the noise at the target spatial location is a plurality of spatial noise sources, the speaker 130 may output target signals corresponding to the plurality of spatial noise sources based on the noise reduction signal. For example, if the plurality of spatial noise sources include a first spatial noise source and a second spatial noise source, the speaker 130 may output a first target signal having an approximately opposite phase and approximately equal amplitude to the noise of the first spatial noise source to cancel the first spatial noise. The noise of the noise source and the noise of the second spatial noise source are approximately opposite in phase and approximately equal in amplitude to the second target signal to cancel the noise of the second spatial noise source. In some embodiments, when the loudspeaker 130 is an air conduction loudspeaker, the position where the target signal and the ambient noise are canceled may be the target spatial position. The distance between the target space position and the user's ear canal is small, and the noise at the target space position can be approximately regarded as the noise at the user's ear canal position. Therefore, the noise reduction signal and the noise at the target space position cancel each other out, and can be approximately transmitted to the user. The ambient noise of the ear canal is eliminated, and the active noise reduction of the acoustic device 100 is realized. In some embodiments, when the loudspeaker 130 is a bone conduction loudspeaker, the position where the target signal and the ambient noise are canceled may be the basilar membrane. The target signal and ambient noise are canceled at the basilar membrane of the user, thereby realizing active noise reduction of the acoustic device 100 .

It should be noted that the above description about the process 300 is only for example and illustration, and does not limit the scope of application of the present application. For those skilled in the art, various modifications and changes can be made to the process 300 under the guidance of the present application. For example, steps in flow 300 may also be added, omitted, or combined. For another example, signal processing (eg, filtering processing, etc.) may also be performed on the environmental noise. Such corrections and changes are still within the scope of this application.

4 is an exemplary noise reduction flow diagram of an acoustic device according to some embodiments of the present application. In some embodiments, process 400 may be performed by acoustic device 100 . As shown in FIG. 4, the process 400 may include:

In step 410, ambient noise is picked up. In some embodiments, this step may be performed by microphone array 110 . In some embodiments, step 410 may be performed in a similar manner to step 310, and the related description is not repeated here.

In step 420, the noise of the target spatial location is estimated based on the picked-up ambient noise. In some embodiments, this step may be performed by processor 120. In some embodiments, step 420 may be performed in a similar manner to step 320, and the related description is not repeated here.

In step 430, the sound field of the target spatial location is estimated. In some embodiments, this step may be performed by processor 120 .

In some embodiments, the processor 120 may utilize the microphone array 110 to estimate the sound field of the target spatial location. Specifically, the processor 120 may construct a virtual microphone based on the microphone array 110 and estimate the sound field of the target spatial position based on the virtual microphone. For more content about estimating the sound field of the target spatial position based on the virtual microphone, reference may be made to other places in the specification of this application, for example, FIGS. 9-10 and their corresponding descriptions.

In step 440, a noise reduction signal is generated based on the noise at the target spatial location and the sound field estimate at the target spatial location. In some embodiments, step 440 may be performed by processor 120 .

In some embodiments, the processor 120 may obtain sound field-related physical quantities (for example, sound pressure, sound frequency, sound amplitude, sound phase, sound source vibration velocity, or medium (for example, air) according to the sound field obtained in step 430 ) density, etc.), adjust the parameter information (eg, frequency information, amplitude information, phase information) of the noise of the target spatial position to generate a noise reduction signal. For example, the processor 120 may determine whether the physical quantity (eg, sound frequency, sound amplitude, sound phase) related to the sound field is the same as the parameter information of the noise at the target spatial location. If the physical quantity related to the sound field is the same as the parameter information of the noise at the target spatial position, the processor 120 may not adjust the parameter information of the noise at the target spatial position. If the physical quantity related to the sound field is different from the parameter information of the noise at the target spatial position, the processor 120 may determine the difference between the physical quantity related to the sound field and the parameter information of the noise at the target spatial position, and adjust the target based on the difference The parameter information of the noise at the spatial location. Just as an example, when the difference is greater than a certain range, the processor 120 may take the average value of the physical quantity related to the sound field and the parameter information of the noise at the target space position as the adjusted parameter information of the noise at the target space position and based on the adjusted value The parameter information of the noise at the target spatial location generates a noise reduction signal. For another example, since the noise in the environment is constantly changing, when the processor 120 generates the noise reduction signal, the noise of the target spatial position in the actual environment may have changed slightly. Therefore, the processor 120 can pick up the ambient noise according to the microphone array. The time information and current time information of the target space position and the physical quantities related to the sound field of the target space position (for example, the vibration velocity of the sound source, the density of the medium (for example, air)) estimate the change amount of the parameter information of the environmental noise of the target space position, and based on the change amount Parameter information for adjusting the noise at the spatial location of the target. After the above adjustment, the amplitude information and frequency information of the noise reduction signal can be more consistent with the amplitude information and frequency information of the environmental noise at the current target spatial position, and the phase information of the noise reduction signal is inversely related to the environmental noise at the current target spatial position. The phase information is more consistent, so that the noise reduction signal can more accurately eliminate ambient noise, improve the noise reduction effect and the user's listening experience.

In some embodiments, when the position of the acoustic device 100 changes, for example, when the head of the user wearing the acoustic device 100 rotates, the ambient noise (eg, noise direction, amplitude, phase) changes accordingly, the acoustic device 100 The speed of performing noise reduction is difficult to keep up with the speed of environmental noise changes, resulting in the failure of the active noise reduction function and even the increase of noise. To this end, the processor 120 may be based on motion information (eg, motion trajectory, motion direction, motion speed, motion acceleration, motion angular velocity, motion-related time information) of the acoustic device 100 obtained by one or more sensors 140 of the acoustic device 100 . Update the noise at the target space location and the sound field estimate at the target space location. Further, the processor 120 may generate a noise reduction signal based on the updated noise at the target spatial location and the sound field estimate at the target spatial location. One or more sensors 140 can record the motion information of the acoustic device 100, and then the processor 120 can quickly update the noise reduction signal, which can improve the noise tracking performance of the acoustic device 100, so that the noise reduction signal can more accurately eliminate the environment noise, further improving the noise reduction effect and the user's listening experience.

In some embodiments, the processor 120 may divide the picked-up ambient noise into multiple frequency bands. Multiple frequency bands correspond to different frequency ranges. For example, the processor 120 may divide the picked-up ambient noise into four frequency bands of 100-300 Hz, 300-500 Hz, 500-800 Hz, and 800-1500 Hz. In some embodiments, each frequency band includes parameter information (eg, frequency information, amplitude information, phase information) of environmental noise in a corresponding frequency range. For at least one of the plurality of frequency bands, the processor 120 may perform steps 420-440 thereon to generate a noise reduction signal corresponding to each of the at least one frequency band. For example, the processor 120 may perform steps 420-440 on the four frequency bands, the frequency bands 300-500 Hz and the frequency bands 500-800 Hz, to generate noise reduction signals corresponding to the frequency bands 300-500 Hz and 500-800 Hz, respectively. Further, in some embodiments, the speaker 130 may output the target signal corresponding to each frequency band based on the noise reduction signal corresponding to each frequency band. For example, the speaker 130 may output a target signal that is approximately opposite in phase and approximately equal in amplitude to the noise in the frequency band 300-500 Hz to cancel the noise in the frequency band 300-500 Hz, and the target signal approximately opposite in phase and approximately equal in amplitude to the noise in the frequency band 500-800 Hz signal to cancel the noise in the frequency band 500-800Hz.

In some embodiments, the processor 120 may also update the noise reduction signal according to the user's manual input. For example, when the user wears the acoustic device 100 to play music in a relatively noisy external environment, the user's own hearing experience effect is not ideal, and the user can manually adjust the parameter information (for example, frequency information, phase information, phase information, etc.) of the noise reduction signal according to the user's own hearing effect. information, amplitude information). For another example, when a special user (eg, a hearing-impaired user or an older user) uses the acoustic device 100, the hearing ability of the special user is different from that of an ordinary user, and the noise reduction signal generated by the acoustic device 100 itself It cannot meet the needs of special users, resulting in poor listening experience for special users. In this case, the adjustment multiples of the parameter information of the noise reduction signal can be preset, and special users can adjust the noise reduction signal according to their own hearing effects and the preset adjustment multiples of the parameter information of the noise reduction signal, so as to update the noise reduction signal. To improve the listening experience of special users. In some embodiments, the user can manually adjust the noise reduction signal through keys on the acoustic device 100 . In other embodiments, the user may adjust the noise reduction signal through the terminal device. Specifically, the parameter information of the noise reduction signal suggested to the user can be displayed on the acoustic device 100 or an external device (eg, mobile phone, tablet computer, computer) in communication with the acoustic device 100, and the user can perform parameter information according to their own hearing experience. fine-tuning.

It should be noted that the above description about the process 400 is only for example and illustration, and does not limit the scope of application of the present application. Various modifications and changes to the process 400 may be made to those skilled in the art under the guidance of the present application. For example, steps in flow 400 may also be added, omitted, or combined. Such corrections and changes are still within the scope of this application.

5A-D are schematic diagrams of exemplary arrangements of microphone arrays (eg, microphone array 110 ) according to some embodiments of the present application. In some embodiments, the arrangement of the microphone array may be a regular geometric shape. As shown in FIG. 5A, the microphone array may be a linear array. In some embodiments, the arrangement of the microphone array can also be in other shapes. For example, as shown in FIG. 5B, the microphone array may be a cross-shaped array. For another example, as shown in FIG. 5C , the microphone array may be a circular array. In some embodiments, the arrangement of the microphone array may also be of irregular geometry. For example, as shown in Figure 5D, the microphone array may be an irregular array. It should be noted that the arrangement of the microphone arrays is not limited to the linear arrays, cross-shaped arrays, circular arrays, and irregular arrays shown in FIGS. Arrays, planar arrays, stereoscopic arrays, radial arrays, etc., are not limited in this application.

In some embodiments, each of the short solid lines in FIGS. 5A-D may be considered a microphone or a group of microphones. When each short solid line is regarded as a group of microphones, the number of each group of microphones may be the same or different, the types of each group of microphones may be the same or different, and the orientation of each group of microphones may be the same or different. The type, quantity and orientation of the microphones can be adaptively adjusted according to the actual application, which is not limited in this application.

In some embodiments, the microphones in the microphone array may be uniformly distributed. The uniform distribution here may refer to the same spacing between any two adjacent microphones in the microphone array. In some embodiments, the microphones in the microphone array may also be non-uniformly distributed. The non-uniform distribution here may mean that the spacing between any two adjacent microphones in the microphone array is different. The spacing between the microphones in the microphone array can be adaptively adjusted according to the actual situation, which is not limited in this application.

6A-B are schematic diagrams of exemplary arrangements of microphone arrays (eg, microphone array 110 ) according to some embodiments of the present application. As shown in FIG. 6A , when the user wears an acoustic device with a microphone array, the microphone arrays are arranged at or around the human ear in a semicircular arrangement. As shown in FIG. 6B , the microphone arrays are arranged in a linear arrangement. The way of cloth is set at the human ear. It should be noted that the arrangement of the microphone arrays is not limited to the semicircular and linear shapes shown in FIGS. 6A and 6B , and the arrangement positions of the microphone arrays are not limited to the positions shown in FIGS. 6A and 6B . The circular and linear shapes and placement of the microphone arrays are for illustrative purposes only.

FIG. 7 is an exemplary flowchart of estimating noise at a spatial location of a target according to some embodiments of the present application. As shown in FIG. 7, process 700 may include:

In step 710, one or more sources of spatial noise related to ambient noise picked up by the microphone array are determined. In some embodiments, this step may be performed by processor 120 . As described herein, determining a spatial noise source refers to determining information related to the spatial noise source, such as the location of the spatial noise source (including the orientation of the spatial noise source, the distance between the spatial noise source and the target spatial location, etc.), the spatial noise source The phase and the amplitude of the spatial noise source, etc.

In some embodiments, a spatial noise source related to ambient noise refers to a noise source whose sound waves can be delivered to the user's ear canal (eg, a target spatial location) or near the user's ear canal. In some embodiments, the spatial noise sources may be noise sources in different directions (eg, front, rear, etc.) of the user's body. For example, there is crowd noise in front of the user's body and vehicle whistle noise to the left of the user's body. In this case, the spatial noise sources include crowd noise sources in front of the user's body and vehicle whistle noise sources to the left of the user's body. In some embodiments, a microphone array (eg, the microphone array 110 ) can pick up spatial noise in all directions of the user's body, and convert the spatial noise into electrical signals and transmit them to the processor 120 , and the processor 120 can process the electrical signals corresponding to the spatial noise. After analysis, parameter information (eg, frequency information, amplitude information, phase information, etc.) of the picked up spatial noise in various directions is obtained. The processor 120 determines the information of the spatial noise sources in various directions according to the parameter information of the spatial noise in various directions, for example, the azimuth of the spatial noise source, the distance of the spatial noise source, the phase of the spatial noise source, and the amplitude of the spatial noise source. In some embodiments, the processor 120 may determine the source of the spatial noise through a noise localization algorithm based on the spatial noise picked up by the microphone array (eg, the microphone array 110). The noise localization algorithm may include one or more of a beamforming algorithm, a super-resolution spatial spectrum estimation algorithm, a time difference of arrival algorithm (also referred to as a delay estimation algorithm), and the like. The beamforming algorithm is a sound source localization method based on controllable beamforming of maximum output power. By way of example only, beamforming algorithms may include Steering Response Power-Phase Transform (SPR-PHAT) algorithms, delay-and-sum beamforming, differential microphone algorithms, sidelobes Cancellation (Generalized Sidelobe Canceller, GSC) algorithm, Minimum Variance Distortionless Response (Minimum Variance Distortionless Response, MVDR) algorithm, etc. Super-resolution spatial spectral estimation algorithms can include autoregressive AR models, minimum variance spectral estimation (MV), and eigenvalue decomposition methods (for example, Multiple Signal Classification (MUSIC) algorithms), etc., which can be obtained by acquiring microphone arrays. The picked-up sound signal (eg, spatial noise) is used to calculate the correlation matrix of the spatial spectrum and efficiently estimate the direction of the spatial noise source. The time difference of arrival algorithm can first estimate the sound arrival time difference, and obtain the sound delay (Time Difference Of Arrival, TDOA) between the microphones in the microphone array, and then use the obtained sound arrival time difference, combined with the known spatial position of the microphone array to further Locate the location of spatial noise sources.

For example, the time delay estimation algorithm can determine the location of the noise source by calculating the time difference between the ambient noise signal and different microphones in the microphone array. For another example, the SPR-PHAT algorithm can perform beamforming in the direction of each noise source, and the direction with the strongest beam energy can be approximately regarded as the direction of the noise source. For another example, the MUSIC algorithm may perform eigenvalue decomposition on the covariance matrix of the environmental noise signal picked up by the microphone array to obtain the subspace of the environmental noise signal, thereby separating the direction of the environmental noise. For more details on determining noise sources, reference may be made to other places in the specification of this application, eg, FIG. 8 and its corresponding description.

In some embodiments, a spatial super-resolution image of environmental noise can be formed by methods such as synthetic aperture, sparse restoration, co-prime array, etc., and the spatial super-resolution image can be used to reflect the signal reflection map of environmental noise, so as to further improve the source of spatial noise. positioning accuracy.

In some embodiments, the processor 120 may divide the picked-up environmental noise into multiple frequency bands according to a specific frequency bandwidth (for example, every 500 Hz as a frequency band), each frequency band may correspond to a different frequency range, and at least one The spatial noise source corresponding to the frequency band is determined on the frequency band. For example, the processor 120 may perform signal analysis on the frequency bands divided by the environmental noise, obtain parameter information of the environmental noise corresponding to each frequency band, and determine the spatial noise source corresponding to each frequency band according to the parameter information. For another example, the processor 120 may determine a spatial noise source corresponding to each frequency band through a noise localization algorithm.

In step 720, the noise of the target spatial location is estimated based on the spatial noise sources. In some embodiments, this step may be performed by processor 120 . As described herein, estimating the noise at the target spatial position refers to estimating parameter information of the noise at the target spatial position, such as frequency information, amplitude information, phase information, and the like.

In some embodiments, the processor 120 may estimate that each spatial noise source respectively transmits the parameter information (eg, frequency information, amplitude information, phase information, etc.) of the spatial noise sources located in various directions of the user's body obtained in step 710 . The parameter information of the noise to the target space position, so as to estimate the noise of the target space position. For example, if there is a spatial noise source in the first orientation (eg, front) and the second orientation (eg, behind) of the user's body, the processor 120 may determine the location information, frequency information, phase information or amplitude of the spatial noise source according to the first orientation. value information, the frequency information, phase information or amplitude information of the first azimuth spatial noise source is estimated when the noise of the first azimuth spatial noise source is transmitted to the target spatial position. The processor 120 may estimate the frequency information of the second azimuth spatial noise source when the noise of the second azimuth spatial noise source is transmitted to the target spatial position according to the position information, frequency information, phase information or amplitude information of the second azimuth spatial noise source. , phase information or amplitude information. Further, the processor 120 may estimate the noise information of the target spatial position based on the frequency information, phase information or amplitude information of the first azimuth spatial noise source and the second azimuth spatial noise source, thereby estimating the noise information of the noise of the target spatial position. For example only, the processor 120 may estimate noise information for the target spatial location using virtual microphone techniques or other methods. In some embodiments, the processor 120 may extract parameter information of the noise of the spatial noise source from the frequency response curve of the spatial noise source picked up by the microphone array through a feature extraction method. In some embodiments, the method for extracting the parameter information of the noise of the spatial noise source may include, but is not limited to, Principal Components Analysis (PCA), Independent Component Algorithm (ICA), Linear Discriminant Analysis (Linear Discriminant) Analysis, LDA), singular value decomposition (Singular Value Decomposition, SVD) and so on.

It should be noted that the above description about the process 700 is only for example and illustration, and does not limit the scope of application of the present application. Various modifications and changes to the process 700 may be made to those skilled in the art under the guidance of the present application. For example, the process 700 may further include the steps of locating the spatial noise source, extracting noise parameter information of the spatial noise source, and the like. For another example, step 710 and step 720 may be combined into one step. Such corrections and changes are still within the scope of this application.

FIG. 8 is a schematic diagram of estimating noise at a spatial position of a target according to some embodiments of the present application. The following takes the time difference of arrival algorithm as an example to illustrate how the location of the spatial noise source is realized. As shown in FIG. 8 , a processor (eg, processor 120 ) may calculate noise signals generated by noise sources (eg, 811 , 812 , 813 ) to pass to different microphones (eg, microphone 821 , microphone 822 , etc.) in microphone array 820 ), and then combined with the known spatial position of the microphone array 820 to determine the position of the noise source through the positional relationship (eg, distance, relative azimuth) between the microphone array 820 and the noise source.

After obtaining the location of the noise source (eg, 811, 812, 813), the processor can estimate the phase delay and amplitude change of the noise signal emitted by the noise source from the noise source to the target spatial location 830 according to the location of the noise source. According to the phase delay, amplitude change and parameter information (eg, frequency information, amplitude information, phase information, etc.) of the noise signal emitted by the spatial noise source, the processor can obtain the parameter information when the environmental noise is transmitted to the target spatial location 830 (eg, frequency information, amplitude information, phase information, etc.), thereby estimating the noise at the spatial location of the target.

It should be noted that the

noise sources

811, 812 and 813, the microphone array 820, the

microphones

821 and 822 in the microphone array 820, and the target spatial position 830 described in FIG. Scope of application. Various modifications and changes will occur to those skilled in the art under the guidance of this application. For example, the microphones in the microphone array 820 are not limited to the microphone 821 and the microphone 822, and the microphone array 820 may also include more microphones and the like. Such corrections and changes are still within the scope of this application.

FIG. 9 is an exemplary flowchart of estimating noise and sound field at a spatial location of a target according to some embodiments of the present application. As shown in FIG. 9, the process 900 may include:

In step 910, a virtual microphone is constructed based on the microphone array (eg, microphone array 110, microphone array 820). In some embodiments, this step may be performed by processor 120 .

In some embodiments, a virtual microphone may be used to represent or simulate audio data collected by the microphone if the microphone is placed at the target spatial location. That is, the audio data obtained by the virtual microphone can be approximated or equivalent to the audio data collected by the physical microphone if the physical microphone is placed at the target spatial position.

In some embodiments, the virtual microphone may include a mathematical model. The mathematical model can embody the relationship between the noise or sound field estimation of the target spatial location and the parameter information (eg, frequency information, amplitude information, phase information, etc.) of the ambient noise picked up by the microphone array and parameters of the microphone array. The parameters of the microphone array may include one or more of the arrangement of the microphone array, the spacing between the microphones, the number and position of the microphones in the microphone array, and the like. The mathematical model can be obtained by calculation based on the initial mathematical model and parameters of the microphone array and parameter information (eg, frequency information, amplitude information, phase information, etc.) of the sound (eg, ambient noise) picked up by the microphone array. For example, the initial mathematical model may include parameters and model parameters corresponding to parameters of the microphone array and parameter information of ambient noise picked up by the microphone array. The parameters of the microphone array and the parameter information of the sound picked up by the microphone array and the initial values of the model parameters are brought into the initial mathematical model to obtain the predicted noise or sound field of the target spatial position. This predicted noise or sound field is then compared with the data (noise and sound field estimates) obtained by physical microphones placed at the target spatial location to make adjustments to the model parameters of the mathematical model. Based on the above adjustment method, the mathematical model is obtained by adjusting multiple times through a large amount of data (for example, parameters of the microphone array and parameter information of ambient noise picked up by the microphone array).

In some embodiments, the virtual microphone may include a machine learning model. The machine learning model may be obtained through training based on parameters of the microphone array and parameter information (eg, frequency information, amplitude information, phase information, etc.) of the sound (eg, ambient noise) picked up by the microphone array. For example, the machine learning model is obtained by training an initial machine learning model (eg, a neural network model) using the parameters of the microphone array and the parameter information of the sound picked up by the microphone array as training samples. Specifically, the parameters of the microphone array and the parameter information of the sound picked up by the microphone array can be input into the initial machine learning model, and prediction results (eg, noise and sound field estimation of the target spatial position) can be obtained. This prediction is then compared with data (noise and sound field estimates) obtained from physical microphones set up at the target spatial location to adjust the parameters of the initial machine learning model. Based on the above adjustment method, through a large amount of data (for example, the parameters of the microphone array and the parameter information of the ambient noise picked up by the microphone array), after many iterations, the parameters of the initial machine learning model are optimized until the prediction results of the initial machine learning model match the target. The machine learning model is obtained when the data obtained by the physical microphones set at the spatial location are the same or approximately the same.

Virtual microphone technology can move physical microphones away from locations where microphone placement is difficult (eg, target spatial locations). For example, in order to open the user's ears without blocking the user's ear canal, the physical microphone cannot be set at the position of the user's ear hole (eg, a target spatial position). At this time, the microphone array can be set close to the user's ear without blocking the ear canal through the virtual microphone technology, for example, at the user's auricle, etc., and then a virtual microphone at the position of the user's ear hole can be constructed through the microphone array. The virtual microphone can predict sound data (eg, amplitude, phase, sound pressure, sound field, etc.) at a second location (eg, a target spatial location) using a physical microphone (ie, a microphone array) at a first location. In some embodiments, the sound data of the second position (which may also be called a specific position, such as a target spatial position) predicted by the virtual microphone may be based on the distance between the virtual microphone and the physical microphone (ie, the microphone array), the Type (eg, mathematical model virtual microphone, machine learning virtual microphone), etc. For example, the closer the distance between the virtual microphone and the physical microphone (ie, the microphone array), the more accurate the sound data of the second position predicted by the virtual microphone. For another example, in some specific application scenarios, the sound data of the second position predicted by the machine learning virtual microphone is more accurate than that of the mathematical model virtual microphone. In some embodiments, the position corresponding to the virtual microphone (ie, the second position, for example, the target spatial position) may be near the microphone array, or may be far away from the microphone array.

In step 920, the noise and sound field of the target spatial location is estimated based on the virtual microphone. In some embodiments, this step may be performed by processor 120 .

In some embodiments, when the virtual microphone is a mathematical model, the processor 120 may combine the parameter information (eg, frequency information, amplitude information, phase information, etc.) of the ambient noise picked up by the microphone array in real time with the parameters of the microphone array (eg, , the arrangement of the microphone array, the spacing between each microphone, the number of microphones in the microphone array) are input into the mathematical model as parameters of the mathematical model to estimate the noise and sound field of the target spatial location.

In some embodiments, when the virtual microphone is a machine learning model, the processor 120 may real-time compare the parameter information (eg, frequency information, amplitude information, phase information, etc.) of the ambient noise picked up by the microphone array with the parameters of the microphone array ( For example, the arrangement of the microphone array, the spacing between the individual microphones, the number of microphones in the microphone array) are input into the machine learning model and the noise and sound field of the target spatial location are estimated based on the output of the machine learning model.

It should be noted that the above description about the process 900 is only for example and illustration, and does not limit the scope of application of the present application. Various modifications and changes to process 900 may be made to process 900 under the guidance of the present application to those skilled in the art. For example, step 920 may be divided into two steps to separately estimate the noise and sound field of the target spatial location. Such corrections and changes are still within the scope of this application.

FIG. 10 is a schematic diagram of constructing a virtual microphone according to some embodiments of the present application. As shown in Figure 10, the target spatial location 1010 may be located near the user's ear canal. In order to achieve the purpose of opening the user's ears and not blocking the ear canal, the target spatial position 1010 cannot be provided with a physical microphone, so that the noise and sound field of the target spatial position 1010 cannot be directly estimated through the physical microphone.

In order to estimate the noise and sound field of the target spatial location 1010, a microphone array 1020 may be provided in the vicinity of the target spatial location 1010. For example only, as shown in FIG. 10 , the microphone array 1020 may include a first microphone 1021 , a second microphone 1022 , and a third microphone 1023 . Each microphone in the microphone array 1020 (eg, the first microphone 1021, the second microphone 1022, and the third microphone 1023) can pick up ambient noise in the space where the user is located. According to the parameter information (eg, frequency information, amplitude information, phase information, etc.) of the ambient noise picked up by each microphone in the microphone array 1020 and the parameters of the microphone array 1020 (eg, the arrangement of the microphone array 1020 , the distance between the microphones distance, the number of microphones in the microphone array 1020), the processor 120 can construct a virtual microphone. Further, based on the virtual microphone, the processor 120 can estimate the noise and sound field at the target spatial location 1010 .

It should be noted that the target spatial position 1010 and the microphone array 1020 and the first microphone 1021 , the second microphone 1022 and the third microphone 1023 in the microphone array 1020 described in FIG. Scope of application. Various modifications and changes may be made by those skilled in the art under the guidance of the present application. For example, the microphones in the microphone array 1020 are not limited to the first microphone 1021, the second microphone 1022 and the third microphone 1023, and the microphone array 1020 may also include more microphones and the like. Such corrections and changes are still within the scope of this application.

In some embodiments, the microphone arrays (eg, microphone array 110, microphone array 820, microphone array 1020) may also pick up interfering signals (eg, target signals and other sound signals) from speakers while picking up ambient noise. In order to prevent the microphone array from picking up the interference signal emitted by the speaker, the microphone array can be arranged far away from the speaker. However, when placed far from the speaker, the microphone array may be too far away from the target spatial location to accurately estimate the sound field and/or noise at the target spatial location. In order to solve the above problems, the microphone array can be placed in the target area to minimize the interference signal from the speaker to the microphone array.

In some embodiments, the target area may be the area of minimum sound pressure level of the loudspeaker. The area of minimum sound pressure level may be the area where the sound radiated by the speaker is low. In some embodiments, the loudspeaker may form at least one set of acoustic dipoles. For example, a set of sound signals output from the front of the speaker diaphragm and the back of the diaphragm with approximately opposite phases and approximately the same amplitude can be regarded as two point sound sources. The two point sound sources can form an acoustic dipole or similar acoustic dipoles, and the sound radiated outward has obvious directivity. Ideally, in the direction of the straight line where the two point sound sources are connected, the sound radiated by the speaker is larger, and the radiated sound in other directions is significantly reduced. ) zone speakers radiate minimal sound.

In some embodiments, a speaker (eg, speaker 130 ) in an acoustic device (eg, acoustic device 100 ) may be a bone conduction speaker. When the speaker is a bone conduction speaker and the interference signal is a sound leakage signal of the bone conduction speaker, the target area may be an area with a minimum sound pressure level of the sound leakage signal of the bone conduction speaker. The region with the minimum sound pressure level of the sound leakage signal may refer to the region where the sound leakage signal radiated by the bone conduction speaker is the minimum. The microphone array is arranged in the area with the minimum sound pressure level of the leakage signal of the bone conduction speaker, which can reduce the interference signal of the bone conduction speaker picked up by the microphone array, and can also effectively solve the problem that the microphone array is too far away from the target space, resulting in the inability to accurately estimate the target. The problem of sound field in spatial position.

FIG. 11 is a schematic diagram illustrating the distribution of sound leakage signals in a three-dimensional sound field of a bone conduction speaker at 1000 Hz according to some embodiments of the present application. FIG. 12 is a schematic diagram of the sound leakage signal distribution of the two-dimensional sound field at 1000 Hz of the bone conduction speaker according to some embodiments of the present application. As shown in FIGS. 11-12 , the acoustic device 1100 may include a contact surface 1110 . The contact surface 1110 may be configured to make contact with the user's body (eg, face, ears) when the user wears the acoustic device 1100 . The bone conduction speaker may be disposed inside the acoustic device 1100 . As shown in FIG. 11 , the color on the acoustic device 1100 can represent the sound leakage signal of the bone conduction speaker, and different color depths can represent different sizes of the sound leakage signal. The lighter the color, the greater the sound leakage signal of the bone conduction speaker; the darker the color, the smaller the sound leakage signal of the bone conduction speaker. As shown in FIG. 11 , compared with other areas, the area 1120 where the dotted line is located has a darker color and a smaller sound leakage signal, so the area 1120 where the dotted line is located may be the area with the minimum sound pressure level of the sound leakage signal of the bone conduction speaker. For example only, the microphone array may be placed in the area 1120 where the dotted line is located (eg, position 1) so that less leakage signals are received from the bone conduction speaker.

In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 5-30 dB lower than the maximum output sound pressure of the bone conduction speaker. In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 7-28 dB lower than the maximum output sound pressure of the bone conduction speaker. In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 9-26 dB lower than the maximum output sound pressure of the bone conduction speaker. In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 11-24 dB lower than the maximum output sound pressure of the bone conduction speaker. In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 13-22 dB lower than the maximum output sound pressure of the bone conduction speaker. In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 15-20 dB lower than the maximum output sound pressure of the bone conduction speaker. In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 17-18 dB lower than the maximum output sound pressure of the bone conduction speaker. In some embodiments, the sound pressure in the region of minimum sound pressure level of the bone conduction speaker may be 15dB lower than the maximum output sound pressure of the bone conduction speaker.

The two-dimensional sound field distribution shown in FIG. 12 is a two-dimensional cross-sectional view of the three-dimensional sound field leakage signal distribution of FIG. 11 . As shown in Figure 12, the color on the cross section can represent the sound leakage signal of the bone conduction speaker, and different color depths can represent different sizes of the sound leakage signal. The lighter the color, the greater the sound leakage signal of the bone conduction speaker, and the darker the color, the smaller the sound leakage signal of the bone conduction speaker. As shown in FIG. 12 , compared with other regions, the

regions

1210 and 1220 where the dotted lines are located have darker colors and smaller sound leakage signals. Therefore, the

regions

1210 and 1220 where the dotted lines are located may be the regions where the sound pressure level of the sound leakage signal of the bone conduction speaker is the minimum. For example only, the microphone arrays may be placed in the

regions

1210 and 1220 where the dotted lines are located (eg, position A and position B) so that less leakage signals are received from the bone conduction speakers.

In some embodiments, the vibration signal emitted by the bone conduction speaker is relatively large during the vibration process. Therefore, not only the sound leakage signal of the bone conduction speaker will interfere with the microphone array, but also the vibration signal of the bone conduction speaker will interfere with the microphone array. . Here, the vibration signal of the bone conduction speaker may refer to the vibration of other parts of the acoustic device (eg, the housing, the microphone array) driven by the vibration of the vibration part of the bone conduction speaker. In this case, the interference signal of the bone conduction speaker may include sound leakage signal and vibration signal of the bone conduction speaker. In order to prevent the microphone array from picking up the interference signal of the bone conduction speaker, the target area where the microphone array is located may be an area where the total energy of the sound leakage signal and the vibration signal of the bone conduction speaker transmitted to the microphone array is the smallest. The sound leakage signal and the vibration signal of the bone conduction speaker are relatively independent signals, and the region with the minimum sound pressure level of the sound leakage signal of the bone conduction speaker cannot represent the region with the minimum total energy of the sound leakage signal and the vibration signal of the bone conduction speaker. Therefore, the determination of the target area needs to analyze the total signal of the vibration signal and the leakage signal of the bone conduction speaker.

FIG. 13 is a schematic diagram of the frequency response of the total signal of the vibration signal and the sound leakage signal of the bone conduction speaker according to some embodiments of the present application. FIG. 13 shows the frequency response curves of the total signal of the vibration signal and the leakage signal of the bone conduction speaker at

positions

1, 2, 3 and 4 on the acoustic device 1100 in FIG. 11 . As shown in FIG. 13 , the abscissa may represent the frequency, and the ordinate may represent the sound pressure of the total signal of the vibration signal and the sound leakage signal of the bone conduction speaker. According to the related description of FIG. 11 , when only considering the sound leakage signal of the bone conduction speaker, the position 1 is located in the area with the minimum sound pressure level of the speaker 130 , which can be used as the target for setting the microphone array (eg, the microphone array 110 , the microphone array 820 , and the microphone array 1020 ). area. When considering both the vibration signal and the leakage signal of the bone conduction speaker, the target area of the microphone array (ie the area where the total signal of the vibration signal and the leakage signal of the bone conduction speaker has the smallest sound pressure) is not necessarily Position 1. Referring to Fig. 13 , compared with other positions, the sound pressure of the total signal of the vibration signal and the sound leakage signal of the bone conduction speaker corresponding to position 2 is relatively small, therefore, position 2 can be used as the target area for setting the microphone array.

In some embodiments, the location of the target area may be related to the orientation of the diaphragms of the microphones in the microphone array. The orientation of the diaphragm of the microphone can affect the magnitude of the vibration signal of the bone conduction speaker received by the microphone. For example, when the diaphragm of the microphone is perpendicular to the vibration component of the bone conduction speaker, the vibration signal of the bone conduction speaker that can be collected by the microphone is small. For another example, when the diaphragm of the microphone is parallel to the vibration component of the bone conduction speaker, the vibration signal of the bone conduction speaker that can be collected by the microphone is larger. In some embodiments, the vibration signal of the bone conduction speaker received by the microphone can be reduced by setting the orientation of the microphone diaphragm. For example, when the diaphragm of the microphone is perpendicular to the vibration component of the bone conduction speaker, the vibration signal of the bone conduction speaker can be ignored in the process of determining the target position for setting the microphone array, and only the sound leakage signal of the bone conduction speaker is considered, that is, according to Figure 11 and the description of FIG. 12 to determine the target position for setting the microphone array. For another example, when the diaphragm of the microphone is parallel to the vibration component of the bone conduction speaker, the vibration signal and the sound leakage signal of the bone conduction speaker can be considered in the process of determining the target position for setting the microphone array, that is, the setting is determined according to the description in FIG. 13 . The target position of the microphone array.

In some embodiments, the phase of the vibration signal of the bone conduction speaker received by the microphone can be adjusted by adjusting the orientation of the diaphragm of the microphone, so that the vibration signal of the bone conduction speaker received by the microphone and the leakage of the bone conduction speaker received by the microphone The phase of the sound signal is approximately opposite and the magnitude is approximately equal, so that the vibration signal of the bone conduction speaker received by the microphone and the sound leakage signal of the bone conduction speaker received by the microphone can be at least partially canceled, so as to reduce the amount of noise received by the microphone array. The interference signal emitted by the bone conduction speaker. In some embodiments, the vibration signal of the bone conduction speaker received by the microphone can reduce the sound leakage signal of the bone conduction speaker received by the microphone by 5-6 dB.

In some embodiments, a speaker (eg, speaker 130 ) in an acoustic device (eg, acoustic device 100 ) may be an air conduction speaker. When the loudspeaker is an air-conductive loudspeaker and the interference signal is a sound signal (ie, a radiated sound field) emitted by the air-conducted loudspeaker, the target area may be an area with a minimum sound pressure level of the radiated sound field of the air-conducted loudspeaker. The microphone array is arranged in the area with the minimum sound pressure level of the radiated sound field of the air conduction speaker, which can reduce the interference signal of the air conduction speaker picked up by the microphone array, and can also effectively solve the problem that the microphone array is too far away from the target space and cannot accurately estimate the target space. The position of the sound field is the problem.

14A-B are schematic diagrams of sound field distribution of an air conduction speaker according to some embodiments of the present application. As shown in Figures 14A-B, the air-conducting speakers may be disposed within the open acoustic device 1400 and radiate sound outward from two sound guiding holes (eg, 1401 and 1402 in Figures 14A-B) of the open acoustic device 1400, And the emitted sound can form a dipole (represented by "+", "-" shown in Figures 14A-B).

As shown in FIG. 14A, the open acoustic device 1400 is positioned so that the line connecting the dipoles is approximately perpendicular to the user's face area. In this case, the sound radiated by the dipole can form three stronger

sound field regions

1421, 1422 and 1423). Between the

sound field regions

1421 and 1423 and between the

sound field regions

1422 and 1423, the minimum sound pressure level region (also called the region with low sound pressure) of the radiated sound field of the air conduction speaker can be formed, for example, the dotted line in FIG. 14A and its nearby area. The minimum sound pressure level region may refer to a region where the sound intensity output by the open acoustic device 1400 is relatively small. In some embodiments, the microphones 1430 in the microphone array may be positioned in the region of minimum sound pressure level. For example, the microphone 1430 in the microphone array can be set at the position where the dotted line in FIG. 14 intersects the housing of the open acoustic device 1400, so that the microphone 1430 can receive as little noise from the air conduction speaker as possible while collecting the external ambient noise. The sound signal reduces the interference of the sound signal emitted by the air conduction speaker to the active noise reduction function of the open acoustic device 1400 .

As shown in FIG. 14B, the open acoustic device 1400 is positioned so that the lines connecting the dipoles are approximately parallel to the user's face area. In this case, the sound radiated by the dipole can form two stronger sound field regions 1424 and 1425). Between the

sound field regions

1424 and 1425, a minimum sound pressure level region of the radiated sound field of the air conduction speaker may be formed, for example, the dashed line in FIG. 14B and its vicinity. In some embodiments, the microphones 1440 in the microphone array may be positioned in the region of minimum sound pressure level. For example, the microphone 1440 in the microphone array can be set at the position where the dotted line in FIG. 14 intersects with the casing of the open acoustic device 1400, so that the microphone 1440 can collect the external ambient noise and receive as little sound from the air conduction speaker as possible. Signal, reducing the interference of the sound signal emitted by the air conduction speaker to the active noise reduction function of the open acoustic device 1400.

FIG. 15 is an exemplary flowchart of outputting a target signal based on a transfer function according to some embodiments of the present application. As shown in Figure 15, process 1500 may include:

In step 1510, the noise reduction signal is processed based on the transfer function. In some embodiments, this step may be performed by the processor 120 (eg, the amplitude and phase compensation unit 230). For more information on noise reduction signals, reference can be made elsewhere in this application, eg, FIG. 3 and its corresponding description. In addition, according to the description of FIG. 3 , the speaker (eg, the speaker 130 ) may output the target signal based on the noise reduction signal generated by the processor 120 .

In some embodiments, the target signal output by the speaker can be transmitted to a specific position in the user's ear (also referred to as a noise cancellation position) through a first sound path, and ambient noise can be transmitted to a specific position of the user's ear through a second sound path , and at a specific location, the target signal and the ambient noise cancel each other out, so that the user cannot perceive the ambient noise or can perceive the relatively weak ambient noise. In some embodiments, when the loudspeaker is an air-conducting loudspeaker, the specific location where the target signal and the ambient noise cancel each other out may be the user's ear canal or its vicinity, eg, the target spatial location. The first sound path may be the path through which the target signal is transmitted from the air conduction speaker to the target spatial position through the air, and the second sound path may be the path through which the ambient noise is transmitted from the noise source to the target spatial position. In some embodiments, when the speaker is a bone conduction speaker, the specific position where the target signal and the ambient noise cancel each other may be at the user's basilar membrane. The first sound path may be the path of the target signal from the bone conduction speaker, through the user's bone or tissue to the user's basement membrane, and the second sound path may be the path of the ambient noise from the noise source, through the user's ear canal, tympanic membrane to the user's basement membrane path.

In some embodiments, the speaker (eg, speaker 130) may be positioned near and not obstructing the user's ear canal, so that the speaker is at a distance from the noise cancellation location (eg, target spatial location, basilar membrane). Therefore, when the target signal output by the speaker is delivered to the noise cancellation position, the phase information and amplitude information of the target signal may change. As a result, it may occur that the target signal output by the speaker cannot achieve the effect of reducing the ambient noise signal, or even enhance the ambient noise, thereby causing the active noise reduction function of the acoustic device (eg, the open acoustic output device 100 ) to fail to achieve.

Based on the above situation, the processor 120 can obtain the transfer function of the target signal emitted from the speaker to the noise canceling position. The transfer functions may include a first transfer function and a second transfer function. The first transfer function may represent the change (eg, change in amplitude, change in phase) of a parameter of the target signal with the sound path (ie, the first sound path) from the loudspeaker to the noise cancellation position. In some embodiments, when the speaker is a bone conduction speaker, the target signal emitted by the bone conduction speaker is the bone conduction signal, and the position where the target signal emitted by the bone conduction speaker and the ambient noise are canceled is the basement membrane of the user. In this case, the first transfer function may represent the change in the parameters (eg, phase, amplitude) of the target signal emanating from the bone conduction speaker to the basilar membrane delivered to the user. In some embodiments, when the speaker is a bone conduction speaker, the first transfer function can be obtained experimentally. For example, the bone conduction speaker outputs the target signal, and at the same time, an air conduction sound signal with the same frequency as the target signal is played near the ear canal of the user, and the cancellation effect of the target signal and the air conduction sound signal is observed. When the target signal and the air conduction sound signal cancel each other, the first transfer function of the bone conduction speaker can be obtained based on the air conduction sound signal and the target signal output by the bone conduction speaker. In some embodiments, when the loudspeaker is an air-conducting loudspeaker, the signal emitted by the air-conducting loudspeaker to the target is an air-conducting sound signal, and the first transfer function can be obtained by simulation and calculation of an acoustic diffusion field. For example, the sound field of the target signal emitted by the air-conducting speaker can be simulated by using the acoustic diffusion field, and the first transfer function of the air-conducting speaker can be calculated based on the sound field. The second transfer function may represent a change in a parameter of the ambient noise (eg, change in amplitude, change in phase) from a target spatial location to a location where the target signal and ambient noise cancel. For example only, when the speaker is a bone conduction speaker, the second transfer function may represent the change in the parameters of the ambient noise from the target spatial location to the basilar membrane of the user. In some embodiments, the second transfer function may be obtained by acoustic diffuse field simulation and calculation. For example, a sound field of ambient noise can be simulated using an acoustic diffuse field, and a second transfer function can be calculated based on the sound field.

In some embodiments, during the transmission of the target signal, there may not only be a phase change, but also energy loss of the signal. Thus the transfer function may include a phase transfer function and an amplitude transfer function. In some embodiments, both the phase transfer function and the magnitude transfer function can be obtained by the above method.

Further, the processor 120 may process the noise reduction signal based on the obtained transfer function. In some embodiments, the processor 120 may adjust the amplitude and phase of the noise reduction signal based on the obtained transfer function. In some embodiments, the processor 120 may adjust the phase of the noise reduction signal based on the obtained phase transfer function and the amplitude of the noise reduction signal based on the magnitude transfer function.

In step 1520, the target signal is output according to the processed noise reduction signal. In some embodiments, this step may be performed by speaker 130 .

In some embodiments, the speaker 130 may output a target signal based on the noise reduction signal processed in step 1510, so that when the target signal output by the speaker 130 based on the processed noise reduction signal is transmitted to a position that cancels out the ambient noise, the target The magnitude of the phase sum of the signal and ambient noise satisfies certain conditions. In some embodiments, the phase difference between the phase of the target signal and the phase of the ambient noise may be less than or equal to a certain phase threshold. The phase threshold may be in the range of 90-180 degrees. The phase threshold can be adjusted within this range according to the user's needs. For example, when the user does not want to be disturbed by the sound of the surrounding environment, the phase threshold may be a larger value, such as 180 degrees, that is, the phase of the target signal is opposite to that of the ambient noise. For another example, when the user wants to be sensitive to the surrounding environment, the phase threshold may be a small value, such as 90 degrees. It should be noted that the more ambient sounds the user wishes to receive, the closer the phase threshold may be to 90 degrees, and the less ambient sounds the user wishes to receive, the closer the phase threshold may be to 180 degrees. In some embodiments, when the phase of the target signal and the phase of the ambient noise are certain (for example, the phases are opposite), the amplitude difference between the amplitude of the ambient noise and the amplitude of the target signal may be less than or equal to a certain amplitude value threshold. For example, when the user does not want to be disturbed by the sound of the surrounding environment, the amplitude threshold may be a small value, such as 0 dB, that is, the amplitude of the target signal is equal to the amplitude of the ambient noise. For another example, when the user wants to be sensitive to the surrounding environment, the amplitude threshold may be a larger value, for example, approximately equal to the amplitude of ambient noise. It should be noted that the more ambient sounds the user wishes to receive, the closer the amplitude threshold can be to the amplitude of ambient noise, and the less ambient sounds the user wishes to receive, the closer the amplitude threshold can be to 0dB. Thus, the purpose of reducing ambient noise and the active noise reduction function of the acoustic device (eg, the acoustic output device 100 ) are achieved, and the user's listening experience is improved.

It should be noted that the above description about the process 1500 is only for example and illustration, and does not limit the scope of application of this specification. Various modifications and changes can be made to the process 1500 to those skilled in the art under the guidance of this specification. For example, the process 1500 may also include the step of obtaining a transfer function. For another example, steps 1510 and 1520 may be combined into one step. Such corrections and changes are still within the scope of this application.

FIG. 16 is an exemplary flowchart for estimating noise at a spatial location of a target, provided according to some embodiments of the present specification. As shown in Figure 16, process 1600 may include:

In step 1610, components associated with the signal picked up by the bone conduction microphone are removed from the picked up ambient noise in order to update the ambient noise.

In some embodiments, this step may be performed by processor 120 . In some embodiments, when the microphone array (eg, the microphone array 110 ) picks up the ambient noise, the user's own speaking voice is also picked up by the microphone array, that is, the user's own speaking voice is also regarded as part of the ambient noise. In this case, the target signal output by the speaker (eg, the speaker 130 ) can cancel the user's own voice. In some embodiments, in certain scenarios, the user's own voice needs to be preserved, for example, in scenarios such as the user making a voice call or sending a voice message. In some embodiments, the acoustic device (eg, the acoustic device 100 ) may include a bone conduction microphone. When the user wears the acoustic device to make a voice call or record voice information, the bone conduction microphone may pick up the vibration signal generated by the facial bones or muscles when the user speaks. to pick up the voice signal of the user speaking, and transmit it to the processor 120 . The processor 120 obtains parameter information from the sound signal picked up by the bone conduction microphone, and removes sound signal components associated with the sound signal picked up by the bone conduction microphone from the ambient noise picked up by the microphone array (eg, the microphone array 110). The processor 120 updates the ambient noise according to the remaining parameter information of the ambient noise. The updated environmental noise no longer includes the sound signal of the user's own speech, that is, the user can hear the sound signal of the user's own speech when the user makes a voice call.

In step 1620, the noise of the target spatial location is estimated according to the updated ambient noise. In some embodiments, this step may be performed by processor 120 . Step 1620 may be performed in a similar manner to step 320, and the related description is not repeated here.

It should be noted that the above description about the process 1600 is only for example and description, and does not limit the scope of application of the present application. Various modifications and changes to process 1600 may be made to process 1600 under the guidance of the present application to those skilled in the art. For example, components associated with the signal picked up by the bone conduction microphone may also be preprocessed, and the signal picked up by the bone conduction microphone may be transmitted to the terminal device as an audio signal. Such corrections and changes are still within the scope of this application.

The basic concept has been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example, and does not constitute a limitation to the present application. Although not explicitly described herein, various modifications, improvements, and corrections to this application may occur to those skilled in the art. Such modifications, improvements, and corrections are suggested in this application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

Meanwhile, the present application uses specific words to describe the embodiments of the present application. References such as "one embodiment," "an embodiment," and/or "some embodiments" mean a certain feature, structure, or characteristic associated with at least one embodiment of the present application. Thus, it should be emphasized and noted that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this application are not necessarily referring to the same embodiment . Furthermore, certain features, structures or characteristics of the one or more embodiments of the present application may be combined as appropriate.

Furthermore, those skilled in the art will appreciate that aspects of this application may be illustrated and described in several patentable categories or situations, including any new and useful process, machine, product, or combination of matter, or combinations of them. of any new and useful improvements. Accordingly, various aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as a "data block", "module", "engine", "unit", "component" or "system". Furthermore, aspects of the present application may be embodied as a computer product comprising computer readable program code embodied in one or more computer readable media.

A computer storage medium may contain a propagated data signal with the computer program code embodied therein, for example, on baseband or as part of a carrier wave. The propagating signal may take a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. Computer storage media can be any computer-readable media other than computer-readable storage media that can communicate, propagate, or transmit a program for use by coupling to an instruction execution system, apparatus, or device. Program code on a computer storage medium may be transmitted over any suitable medium, including radio, cable, fiber optic cable, RF, or the like, or a combination of any of the foregoing.

Furthermore, unless explicitly stated in the claims, the order of processing elements and sequences described in the present application, the use of numbers and letters, or the use of other names are not intended to limit the order of the procedures and methods of the present application. While the foregoing disclosure discusses by way of various examples some embodiments of the invention that are presently believed to be useful, it is to be understood that such details are for purposes of illustration only and that the appended claims are not limited to the disclosed embodiments, but rather The requirements are intended to cover all modifications and equivalent combinations falling within the spirit and scope of the embodiments of the present application. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described systems on existing servers or mobile devices.

Similarly, it should be noted that, in order to simplify the expressions disclosed in the present application and thus help the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, various features are sometimes combined into one embodiment, in the drawings or descriptions thereof. However, this method of disclosure does not imply that the subject matter of the application requires more features than those mentioned in the claims. Indeed, there are fewer features of an embodiment than all of the features of a single embodiment disclosed above.

Some examples use numbers to describe quantities of ingredients and attributes, it should be understood that such numbers used to describe the examples, in some examples, use the modifiers "about", "approximately" or "substantially" to retouch. Unless stated otherwise, "about", "approximately" or "substantially" means that a variation of ±20% is allowed for the stated number. Accordingly, in some embodiments, the numerical parameters set forth in the specification and claims are approximations that can vary depending upon the desired characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and use a general digit reservation method. Notwithstanding that the numerical fields and parameters used in some embodiments of the present application to confirm the breadth of their ranges are approximations, in particular embodiments such numerical values are set as precisely as practicable.

Each patent, patent application, patent application publication, and other material, such as article, book, specification, publication, document, etc., cited in this application is hereby incorporated by reference in its entirety. Application history documents that are inconsistent with or conflict with the content of this application are excluded, as are documents (currently or hereafter appended to this application) that limit the broadest scope of the claims of this application. It should be noted that, if there is any inconsistency or conflict between the descriptions, definitions and/or terms used in the attached materials of this application and the content of this application, the descriptions, definitions and/or terms used in this application shall prevail .

Finally, it should be understood that the embodiments described in the present application are only used to illustrate the principles of the embodiments of the present application. Other variations are also possible within the scope of this application. Accordingly, by way of example and not limitation, alternative configurations of embodiments of the present application may be considered consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments expressly introduced and described in the present application.

Claims

An acoustic device comprising:

an array of microphones, configured to pick up ambient noise;

The processor, configured as:

using the microphone array to estimate a sound field at a target spatial location that is closer to the user's ear canal than any microphone in the microphone array, and

generating a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location; and

at least one speaker configured to output a target signal based on the noise reduction signal, the target signal being used to reduce the ambient noise, wherein the microphone array is positioned in the target area so that the microphone array is affected by the at least one The loudspeaker has minimal interference signals.
The acoustic device of claim 1, wherein the generating a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location comprises:

estimating noise at the target spatial location based on the picked-up ambient noise; and

The noise reduction signal is generated based on noise at the target spatial location and a sound field estimate at the target spatial location.
The acoustic device of claim 2, wherein

The acoustic device further includes one or more sensors for acquiring motion information of the acoustic device, and

The processor is further configured to:

updating the noise of the target spatial location and the sound field estimate of the target spatial location based on the motion information; and

The noise reduction signal is generated based on the updated noise of the target spatial position and the updated sound field estimate of the target spatial position.
The acoustic device of claim 2, wherein the estimating noise of the target spatial location based on the picked-up ambient noise comprises:

determining one or more spatial noise sources associated with the picked-up ambient noise; and

Based on the spatial noise source, the noise of the target spatial location is estimated.
The acoustic device according to claim 1, wherein the estimating the sound field of the target spatial location using the microphone array comprises:

constructing a virtual microphone based on the microphone array, the virtual microphone including a mathematical model or a machine learning model for representing audio data collected by the microphone if the target spatial location includes a microphone; and

The sound field of the target spatial location is estimated based on the virtual microphone.
The acoustic device of claim 5, wherein the generating a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location comprises:

estimating noise at the target spatial location based on the virtual microphone; and

The noise reduction signal is generated based on noise at the target spatial location and a sound field estimate at the target spatial location.
The acoustic device of claim 1, wherein

the at least one speaker is a bone conduction speaker,

The interference signal includes a sound leakage signal and a vibration signal of the bone conduction speaker, and

The target area is an area where the total energy of the leakage signal and the vibration signal transmitted to the bone conduction speaker of the microphone array is the smallest.
The acoustic device of claim 7, wherein,

The position of the target area is related to the orientation of the diaphragms of the microphones in the microphone array,

The orientation of the diaphragm of the microphone reduces the magnitude of the vibration signal of the bone conduction speaker received by the microphone,

The diaphragm of the microphone is oriented such that the vibration signal of the bone conduction speaker received by the microphone and the leakage signal of the bone conduction speaker received by the microphone at least partially cancel each other, and

The vibration signal of the bone conduction speaker received by the microphone reduces the sound leakage signal of the bone conduction speaker received by the microphone by 5-6 dB.
The acoustic device of claim 1, wherein

the at least one speaker is an air conduction speaker, and

The target area is the area with the minimum sound pressure level of the radiated sound field of the air conduction speaker.
The acoustic device of claim 1, wherein

The processor is further configured to process the noise reduction signal based on a transfer function, the transfer function including a first transfer function and a second transfer function, the first transfer function representing the emission from the at least one speaker to the The target signal and the position where the ambient noise cancels the change in the parameter of the target signal, and the second transfer function represents the change of the ambient noise from the target spatial position to the position where the target signal and the ambient noise cancel. changes in parameters; and

The at least one speaker is further configured to output the target signal based on the processed noise reduction signal.
The acoustic device of claim 1, wherein the generating a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location comprises:

dividing the picked-up ambient noise into a plurality of frequency bands, the plurality of frequency bands corresponding to different frequency ranges; and

For at least one of the plurality of frequency bands, a noise reduction signal corresponding to each of the at least one frequency band is generated.
1. The acoustic device of claim 1, wherein the processor is further configured to amplitude and phase adjust the noise of the target spatial location based on the sound field estimate of the target spatial location to generate the noise reduction signal.
2. The acoustic device of claim 1, wherein the acoustic device further comprises a securing structure configured to secure the acoustic device in a position adjacent to the user's ear and not occluding the user's ear canal.
The acoustic device of claim 1, wherein the acoustic device further comprises a housing structure configured to carry or house the microphone array, the processor, and the at least one speaker.
A noise reduction method comprising:

Ambient noise is picked up by the microphone array;

by the processor

Using the microphone array to estimate the sound field of a target spatial position, the target spatial position is closer to the user's ear canal than any microphone in the microphone array;

generating a noise reduction signal based on the picked-up ambient noise and the sound field estimate of the target spatial location; and

A target signal is output from at least one speaker according to the noise reduction signal, the target signal is used to reduce the ambient noise, wherein the microphone array is arranged in the target area so that the microphone array is subjected to the noise from the at least one speaker. Interfering signals are minimal.
16. The noise reduction method of claim 15, wherein the generating, by the processor, a noise reduction signal based on the picked-up ambient noise and the sound field estimation of the target spatial location comprises:

estimating noise at the target spatial location based on the picked-up ambient noise; and

The noise reduction signal is generated based on noise at the target spatial location and a sound field estimate at the target spatial location.
The noise reduction method of claim 16, further comprising:

acquiring motion information of the acoustic device by one or more sensors,

by the processor

updating the noise of the target spatial location and the sound field estimate of the target spatial location based on the motion information; and

The noise reduction signal is generated based on the updated noise of the target spatial position and the updated sound field estimate of the target spatial position.
The noise reduction method according to claim 16, wherein the estimating the noise of the target spatial position based on the picked-up environmental noise comprises:

determining one or more spatial noise sources associated with the picked-up ambient noise; and

Based on the spatial noise source, the noise of the target spatial location is estimated.
The noise reduction method according to claim 15, wherein the estimation by the processor of the sound field of the target spatial position using the microphone array comprises:

constructing a virtual microphone based on the microphone array, the virtual microphone including a mathematical model or a machine learning model for representing audio data collected by the microphone if the target spatial location includes a microphone; and

The sound field of the target spatial location is estimated based on the virtual microphone.
The noise reduction method of claim 19, wherein the generating a noise reduction signal based on the picked-up ambient noise and the sound field estimation of the target spatial position comprises:

estimating noise at the target spatial location based on the virtual microphone; and

The noise reduction signal is generated based on noise at the target spatial location and a sound field estimate at the target spatial location.
The noise reduction method of claim 15, wherein

the at least one speaker is a bone conduction speaker,

The interference signal includes a sound leakage signal and a vibration signal of the bone conduction speaker, and

The target area is an area where the total energy of the leakage signal and the vibration signal transmitted to the bone conduction speaker of the microphone array is the smallest.
The noise reduction method according to claim 21, wherein the position of the target area is related to the orientation of the diaphragms of the microphones in the microphone array.
The noise reduction method of claim 15, wherein

the at least one speaker is an air conduction speaker, and

The target area is the area with the minimum sound pressure level of the radiated sound field of the air conduction speaker.
The noise reduction method of claim 15, further comprising

processing, by the processor, the noise reduction signal based on a transfer function, the transfer function comprising a first transfer function and a second transfer function, the first transfer function representing the signal emitted from the at least one speaker to the target signal and the change of the parameter of the target signal at the position where the ambient noise is canceled, the second transfer function represents the change of the parameter of the ambient noise from the target spatial position to the position where the target signal and the ambient noise are canceled changes; and

The target signal is output by the at least one speaker according to the processed noise reduction signal.