CN108668189B

CN108668189B - Noise reduction method and device for bone conduction earphone and bone conduction earphone

Info

Publication number: CN108668189B
Application number: CN201810459998.XA
Authority: CN
Inventors: 罗强
Original assignee: Shenzhen Vvfly Electronics Co ltd
Current assignee: Shenzhen Vvfly Electronics Co ltd
Priority date: 2018-05-15
Filing date: 2018-05-15
Publication date: 2020-03-13
Anticipated expiration: 2038-05-15
Also published as: CN108668189A

Abstract

The invention is suitable for the technical field of medical signal processing, and provides a noise reduction method and device for a bone conduction earphone and the bone conduction earphone, wherein the noise reduction method and device comprise the following steps: acquiring first sound noise around the auricle of a user to obtain a first waveform of the first sound noise, and calculating a second waveform of second sound noise based on the first waveform, wherein the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point; calculating a time difference value based on the time when the second sound noise is conducted to the auditory nerve in a bone conduction mode and the time when the first sound noise is conducted to the auditory nerve in an air conduction mode; and after delaying the time of the time difference, controlling a vibration source to generate second sound noise in a vibration mode based on the second waveform, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then is superposed with the first sound noise conducted through air at the auditory nerve of the user and then is counteracted. The method is suitable for noise reduction of the bone conduction earphone.

Description

Noise reduction method and device for bone conduction earphone and bone conduction earphone

Technical Field

The invention belongs to the technical field of medical signal processing, and particularly relates to a noise reduction method and device for a bone conduction earphone and the bone conduction earphone.

Background

In daily life, many people have the habit of listening to audio by using earphones, and people listen to music, stories, learning audio and the like by using earphones.

Currently, many types of earphones are sold in the market, such as in-ear earphones, and users need to plug the earphones into the ears when using the earphones, and then a noise reduction system carried by the earphones is added, so that audio files with little noise can be heard. However, such earphones are required to be inserted into the ears, and thus, uncomfortable feeling is brought to the user when the earphones are worn for a long time. Therefore, the bone conduction earphone is born, and the bone conduction earphone can directly transmit sound waves to nerves through bones, so that a user can hear wonderful audio files without plugging the bone conduction earphone into ears.

Although the bone conduction earphone can solve the problem of ear discomfort brought to the user by the in-ear earphone, the bone conduction earphone cannot perform noise reduction processing on the environmental noise like the in-ear earphone, so that the user can always hear various types of environmental noise when listening to the audio file by using the bone conduction earphone.

Disclosure of Invention

In view of this, embodiments of the present invention provide a noise reduction method and apparatus for a bone conduction earphone, and a bone conduction earphone, so as to solve a problem that environmental noise of a bone conduction earphone which is urgently to be solved in the prior art cannot be removed.

A first aspect of an embodiment of the present invention provides a noise reduction method for a bone conduction headset, including: acquiring first sound noise around a user auricle, acquiring a first waveform of the first sound noise, and calculating a second waveform of second sound noise based on the first waveform, wherein the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point; calculating a time difference value based on a time at which the second sound noise is conducted to the auditory nerve of the user by bone conduction and a time at which the first sound noise is conducted to the auditory nerve of the user by air conduction; and after delaying the time of the time difference, controlling a vibration source to generate the second sound noise in a vibration mode based on the second waveform, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then is superposed with the first sound noise conducted through air at the auditory nerve of the user and then is counteracted.

A second aspect of an embodiment of the present invention provides a noise reduction apparatus for a bone conduction headset, including: the device comprises an acquisition module, a processing module and a processing module, wherein the acquisition module is used for acquiring first sound noise around the auricle of a user, acquiring a first waveform of the first sound noise, and calculating a second waveform of second sound noise based on the first waveform, and the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point; a calculation module, configured to calculate a time difference value based on a time when the second sound noise is conducted to the auditory nerve of the user in a bone conduction manner and a time when the first sound noise is conducted to the auditory nerve of the user in an air conduction manner; and the conduction module is used for controlling the vibration source to generate the second sound noise in a vibration mode based on the second waveform after delaying the time of the time difference value, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then is offset after being superposed with the first sound noise conducted through air at the auditory nerve of the user.

A third aspect of an embodiment of the present invention provides a noise reduction system for a bone conduction headset, including: a microprocessor, a vibration source and at least one sound sensor; the sound sensor is used for collecting first sound noise around the auricle of the user; the microprocessor is used for acquiring the first sound noise, obtaining a first waveform of the first sound noise, and calculating a second waveform of a second sound noise based on the first waveform, wherein the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point; calculating a time difference value based on the time when the second sound noise is conducted to the auditory nerve by means of bone conduction and the time when the first sound noise is conducted to the auditory nerve by means of air conduction; outputting a control signal based on the second waveform to the vibration source after delaying the time of the time difference; the vibration source is used for receiving the control signal and generating the second sound noise in a vibration mode based on the control signal, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then is superposed with the first sound noise conducted through air and then is offset.

A fourth aspect of embodiments of the present invention provides a bone conduction headset comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method according to the first aspect when executing the computer program.

A fifth aspect of the embodiments of the present invention provides a computer-readable storage medium, which stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method as described above.

Compared with the prior art, the embodiment of the invention has the following beneficial effects:

the embodiment of the invention provides a noise reduction method and device for a bone conduction earphone and the bone conduction earphone, firstly, a first sound noise is obtained, a first waveform of the first sound noise is obtained, then a second waveform of a second sound noise opposite to the phase of the first sound noise is obtained through calculation, meanwhile, the second sound noise is conducted to an auditory nerve of a user in a bone conduction mode to counteract the first sound noise transmitted into the ear of the user through air, and because the speed of sound conducted to the auditory nerve through the bone conduction and the speed of sound conducted through the air are different, the time difference value is calculated based on the time of the second sound noise conducted to the auditory nerve through the bone conduction mode and the time of the first sound noise conducted to the auditory nerve through the air conduction mode, so as to control a vibration source to generate the second sound noise according to the time difference value, so that the second sound noise and the first sound noise arrive at the auditory nerve at the same time to be cancelled. Since the first acoustic noise conducted into the ear through the air and the calculated reverse noise (i.e., the second acoustic noise) of the first acoustic noise are directly added and cancelled, a good effect can be obtained in reducing or even eliminating the ambient noise conducted into the ear through the air.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 illustrates a schematic diagram of a human ear configuration provided in accordance with an embodiment of the present invention;

fig. 2 shows a flowchart illustrating an implementation of a noise reduction method for a bone conduction headset according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a pinna provided in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram of a first waveform containing a plurality of acoustic noises according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a first waveform and a second waveform having opposite phases according to an embodiment of the present invention;

fig. 6 is a schematic flow chart of an implementation of a noise reduction method for a bone conduction headset according to another embodiment of the present invention;

fig. 7 is a schematic composition diagram of a noise reduction apparatus for a bone conduction headset according to an embodiment of the present invention;

fig. 8 is a schematic composition diagram of a noise reduction system for bone conduction headphones according to an embodiment of the present invention;

fig. 9 is a schematic diagram of a bone conduction headset according to an embodiment of the present invention.

Detailed Description

The sound is actually a vibration wave, also called sound wave, having a certain frequency range and emitted by a certain sounding body. As shown in fig. 1, the auricle of a human body acts as a satellite receiver, which receives sound waves and focuses the sound waves to the external auditory canal, and then enters the human ear through the external auditory canal by air conduction to cause vibration of the tympanic membrane, and further, the vibration of the tympanic membrane can drive the vibration of the ossicle connected with the tympanic membrane and transmit the vibration to the cochlea of the inner ear, the cochlea is filled with biological fluid and is distributed with a plurality of nerve endings, which can convert the transmitted mechanical signals into electrical signals, and the electrical signals are focused to the auditory nerve (i.e., auditory nerve) of the brain and transmitted to the auditory center of the brain through the auditory nerve until the human body really perceives sound. Although this process appears to be complex, the completion of the entire process is within a few thousandths of a second, and humans cannot perceive such small time differences.

The waveform of a single acoustic wave is a standard sine wave, for example, an acoustic wave generated by tapping the tuning fork in the ideal case. The sound we hear in daily life is usually formed by the superposition of a plurality of sine waves.

The sound wave needs to be transmitted by a medium, air, solid and liquid can be used as transmission media of the sound wave, and meanwhile, the transmission speeds of the sound wave in different media are different. The propagation speed of the acoustic wave is determined by the density of the propagation medium, and the higher the density, the faster the propagation. Generally, the sound wave propagates fastest in a solid and slowest in a gas, and the propagation speed of the sound wave in the air is 344m/s, the propagation speed of the sound wave in fresh water is 1430m/s and the propagation speed of the sound wave in steel is 5800m/s under normal temperature and normal pressure.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example one

Fig. 2 shows an implementation flow of a noise reduction method for a bone conduction headset according to an embodiment of the present invention. The main body of the implementation of the noise reduction method for the bone conduction headset in this embodiment is a device which implements the noise reduction method for the bone conduction headset according to the embodiment of the present invention, and the device may include, but is not limited to, the bone conduction headset. The details are as follows:

s101, acquiring first sound noise around a user auricle, obtaining a first waveform of the first sound noise, and calculating a second waveform of second sound noise based on the first waveform, wherein the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point.

The auricle, as shown in fig. 3, is mainly composed of cartilage and has the function of collecting sound waves.

The first sound noise refers to ambient noise of an external sound source collected through a sound sensor in a bone conduction earphone placed on a user's auricle.

The first acoustic noise may include one acoustic noise from one sound source, and may also include acoustic noise from a plurality of sound sources. For example, when the first sound noise includes only one sound noise from one sound source, the first sound noise may include only one sound of a certain broadcast; when the first sound noise includes sound noises from a plurality of sound sources, the first sound noise may include both a broadcast sound and a cry of a bird.

Therefore, the first waveform corresponding to the first acoustic noise may be a time-domain waveform including only a certain sound source, or may be a time-domain waveform including a superposition of a plurality of sound sources, as shown in fig. 4. Specifically, in an ideal case, when the first sound noise is a sound including only one sound from a certain sound source, the first waveform is a sine wave; when the first sound noise includes sounds from a plurality of sound sources, the first waveform is a non-sinusoidal wave.

The second waveform is a waveform of second sound noise calculated based on the first waveform, and the phase of the second waveform is opposite to that of the first waveform at the same time point, as shown in fig. 5. After the second waveform is calculated, a microprocessor in the bone conduction earpiece generates a control signal based on the second waveform to control the vibration source to generate a second sound noise based on the control signal.

In the embodiment of the present invention, the first waveform and the second waveform are both time domain waveforms, and the time domain waveform is a waveform describing a change of a signal with time and is a representation of the signal, and is generally a waveform describing a change of an amplitude of the signal with time, as shown in fig. 5.

The second sound noise is conducted to the auditory nerve of the user in a bone conduction mode to be counteracted with the first sound noise conducted through the air at the auditory nerve, and therefore the first sound noise is reduced or even completely removed.

The phase is a quantity that reflects the amplitude value (i.e., amplitude value) of the signal with respect to time. For example, if the amplitude of the sine wave 1 reaches the maximum and the amplitude of the sine wave 2 reaches the maximum at a certain time point t, the two standard sine waves are said to have the same phase at the time point t; if the amplitude of sine wave 1 is at a maximum and the amplitude of sine wave 2 is at a minimum at a certain time t, the phases of the two sine waves at time t are said to be opposite.

S102, calculating a time difference value based on the time when the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and the time when the first sound noise is conducted to the auditory nerve of the user in an air conduction mode.

The bone conduction mode is a sound conduction mode, in which sound is transmitted to an auditory nerve of a person through a skull and a jaw, and then transmitted to an auditory center in a brain through the auditory nerve, so that the person can hear the sound.

The bone conduction mode can be considered as a mode in which sound is transmitted through a solid body. In this way, it is necessary to first determine the propagation speed of the second sound noise in the skull and the distance from the auricle to the auditory nerve, and then obtain the time for the second sound noise to be conducted to the auditory nerve of the user by bone conduction.

As an embodiment of the present invention, a time for the second sound noise to be conducted to the auditory nerve of the user by bone conduction is set to a constant value. In this case, by default, the propagation speed and the propagation distance of the second sound noise in each person's skull are both equal.

It should be noted that, since the skull size, skull density, external auditory canal length, etc. of each person are not uniform, the propagation speed of the second sound noise in the skull of the person and the distance from the auricle to the auditory nerve of the user are only uniform speed and uniform distance that are approximately suitable for all persons, so as to obtain a time constant value suitable for all persons. Of course, since the speed of sound propagation in a solid is inherently large, the time constant obtained at the end is not much different from the time value calculated from the actual condition of each of the skull and ear, although it varies between each person and ear.

As another embodiment of the present invention, the time when the second sound noise is conducted to the auditory nerve of the user by bone conduction is specifically calculated according to the actual condition of each person.

In this case, the bone conduction earphone may calculate the time of the second sound noise in different human skull based on the propagation speed of the second sound noise in different human skull and the distance from the auricle to the auditory nerve, and conduct the second sound noise to the auditory nerve based on the bone conduction manner, so as to obtain the "time" suitable for each person, so that the calculated time is more accurate, and represents the time difference of sound conduction in different human skull by the bone conduction manner.

The auditory nerve, as shown in fig. 1, is the intermediary medium that transmits signals from the human ear to the brain. Specifically, the electrical signal in the cochlea is converged to the auditory nerve, and then is transmitted to the auditory center of the brain by the auditory nerve, so that a person can hear the sound.

The air conduction mode is another sound conduction mode, in this mode, the sound emitted by the sound source is converged through the auricle of the person, and is conducted in the external auditory canal of the person through the air to cause the vibration of the eardrum, then the vibration of the eardrum drives the ossicle to vibrate, and the vibration is continuously transmitted to the cochlea, and finally is transmitted to the brain auditory center through the auditory nerve to enable the person to hear the sound.

The time difference is a difference between a time when the second sound noise is conducted to the auditory nerve of the user in a bone conduction manner and a time when the first sound noise is conducted to the auditory nerve of the user in an air conduction manner.

In the embodiment of the present invention, since the speed of sound conducted through bone (solid) is faster than that conducted through air, and the conducting paths are different, if the second sound noise and the first sound noise start to be transmitted simultaneously, the second sound noise will necessarily reach the auditory nerve first, and in order to enable the second sound noise and the first sound noise to reach the auditory nerve simultaneously, so as to better offset the noise influence of the first sound noise, it is necessary to calculate the time of transmitting the two sound noises to the auditory nerve of the user from the same time first, obtain the time difference, and then delay the time difference for the second sound noise to start to be transmitted again, so as to offset the first sound noise conducted through air.

And S103, after delaying the time of the time difference, controlling a vibration source to generate the second sound noise in a vibration mode based on the second waveform, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then superposed with the first sound noise conducted through air at the auditory nerve of the user to be offset.

The vibration source, which is disposed in the bone conduction earphone and connected to the microprocessor in the bone conduction earphone, may include, but is not limited to, a vibration motor for generating a second sound noise capable of being cancelled with the first sound noise conducted through the air based on a control signal output from the microprocessor.

In the scheme, the first sound noise is firstly acquired, the first waveform of the first sound noise is obtained, then, a second waveform of a second sound noise having a phase opposite to that of the first sound noise is obtained by calculation, and at the same time, since the second sound noise needs to be conducted to the auditory nerve of the user by bone conduction to cancel the first sound noise conducted into the ear of the user through the air, while since the speed of sound conducted through bone conduction and through the air is different, it is necessary to calculate a time difference value based on the time when the second acoustic noise is conducted to the auditory nerve by bone conduction and the time when the first acoustic noise is conducted to the auditory nerve by air conduction, and controlling the vibration source to generate a second sound noise according to the time difference value, so that the second sound noise and the first sound noise arrive at the auditory nerve at the same time to be counteracted. Since the first acoustic noise conducted into the ear through the air and the calculated reverse noise (i.e., the second acoustic noise) of the first acoustic noise are directly added and cancelled, a good effect can be obtained in reducing or even eliminating the ambient noise conducted into the ear through the air.

As an embodiment of the present invention, in step S101, the calculating a second waveform of a second sound noise based on the first waveform includes: transforming the first waveform from a time domain to a frequency domain by using Fourier transform to obtain a frequency domain waveform of the first waveform; inverting the frequency domain waveform to obtain an inverted frequency domain waveform; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by using inverse Fourier transform to obtain a second waveform of the second sound noise.

The frequency domain waveform is a waveform describing the change of the signal along with the frequency, and is consistent with the time domain waveform, and both are a representation form of the signal.

The fourier transform is a special integral transform, which can represent a certain function satisfying a certain condition as a linear combination or integral of sinusoidal basis functions, and can transform a signal from a time domain to a frequency domain.

Corresponding to the fourier transform is an inverse fourier transform, which is a mathematical operation that can transform a signal from the frequency domain back to the time domain.

In this case, the second sound noise includes only one sound noise of one sound source, and after the time-domain waveform of the sound noise is obtained, because the processing of the time-domain signal is complicated and the analysis is inconvenient, for convenience of analysis and processing, it is necessary to first perform fourier transform to transform the time-domain signal into a frequency domain, and then perform inverse transform on the frequency-domain waveform to obtain an inverse frequency-domain waveform, so as to obtain the time-domain waveform of the second sound noise by performing inverse fourier transform based on the inverse frequency-domain waveform.

As another embodiment of the present invention, in step S101, the acquiring a first sound noise around a pinna of a user to obtain a first waveform of the first sound noise includes: acquiring first sound noise around a user auricle, decomposing the first sound noise to obtain a plurality of first sub-sound noises, and obtaining a first sub-waveform corresponding to each first sub-sound noise; correspondingly, the calculating a second waveform of a second sound noise based on the first waveform comprises: transforming each first sub-waveform from a time domain to a frequency domain by using Fourier transform to obtain a frequency domain sub-waveform of each first sub-waveform; superposing the plurality of frequency domain sub-waveforms to obtain superposed frequency domain waveforms, and inverting the superposed frequency domain waveforms to obtain inverted frequency domain waveforms; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by adopting inverse Fourier transform to obtain a second waveform of the second sound noise.

In this case, since the first sound noise may be a plurality of sound noises from a plurality of sound sources, after the first sound noise is acquired, the acquired first sound noise needs to be decomposed to obtain time domain waveforms of different sound noises, then the waveforms are respectively transformed from the time domain to the frequency domain so as to be analyzed and processed, finally, after the obtained plurality of frequency domain sub-waveforms are overlapped and inverted, the inverted frequency domain waveform is inversely transformed by using an inverse fourier transform to obtain a time domain waveform of the second sound noise.

Example two

Fig. 3 shows an implementation flow of a noise reduction method for a bone conduction headset according to a second embodiment of the present invention. The difference between the second embodiment of the present invention and the first embodiment is in step S201, and other similar parts refer to the related description of the first embodiment. The details are as follows.

S201, acquiring first sound noise around a user auricle, obtaining a first waveform of the first sound noise, and calculating a second waveform of second sound noise if an amplitude value of the first waveform is between a first preset value and a second preset value, wherein phases of the second waveform and the first waveform corresponding to the same time point are opposite.

In the embodiment of the present invention, the amplitude value is a value reflecting the magnitude of the sound noise. If the amplitude value is large, the noise is considered to be large, and if the amplitude value is small, the noise is considered to be small.

The first preset value and the second preset value are two preset values and are set according to actual requirements. For example, when the bone conduction earphone is used by a user with certain hearing impairment, the first preset value and the second preset value can be set as large as possible, because the user cannot hear the bone conduction earphone even though certain noise exists outside due to the hearing impairment; when the bone conduction earphone is used by a user with normal hearing, the first preset value and the second preset value can be set to be relatively smaller as much as possible.

The first preset value and the second preset value are not limited herein, that is, the first preset value may be greater than the second preset value, and the first preset value may also be smaller than the second preset value.

In the embodiment of the invention, whether the second sound noise is generated by the vibration source is judged according to the amplitude value, the first preset value and the second preset value.

S202, calculating a time difference value based on the time when the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and the time when the first sound noise is conducted to the auditory nerve of the user in an air conduction mode.

And S203, after delaying the time of the time difference, controlling a vibration source to generate the second sound noise in a vibration mode based on the second waveform, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then superposed with the first sound noise conducted through air at the auditory nerve of the user to be offset.

According to the scheme, a selectable scheme is provided for the type of the noise to be removed, namely, only when the amplitude value of the first sound noise is between a first preset value and a second preset value, the noise removal is selected for improving the user experience and not causing any influence on the hearing of the user, because when the amplitude value is smaller than the first preset value, the noise is considered to be negligible and the influence on people is small, and at the moment, the noise removal is selected not for reducing the damage of a vibration source to ears; when the amplitude value of the first sound noise is larger than the second preset value, the second sound noise generated by the vibration source is not denoised, because when the noise is too large, the vibration source is made to vibrate to generate the large noise, the hearing of the ears of a person is likely to be damaged, especially if the second sound noise generated at the moment cannot be counteracted with the first sound noise conducted through the air due to some reasons, the two sounds simultaneously and are transmitted to the brain auditory center, and therefore the ears are more damaged, and therefore when the amplitude value of the noise is larger than the second preset value, the mode of denoising by the vibration source in a vibration mode is not adopted.

EXAMPLE III

Fig. 7 shows a schematic composition diagram of a noise reduction apparatus for a bone conduction earphone according to a third embodiment of the present invention, which includes an obtaining unit 110, a calculating unit 120, and a conducting unit 130, and is detailed as follows:

an obtaining module 110, configured to obtain a first sound noise around an auricle of a user, obtain a first waveform of the first sound noise, and calculate a second waveform of a second sound noise based on the first waveform, where a phase of the second waveform is opposite to a phase of the first waveform corresponding to a same time point;

a calculating module 120, configured to calculate a time difference value based on a time when the second sound noise is conducted to the auditory nerve of the user by bone conduction and a time when the first sound noise is conducted to the auditory nerve of the user by air conduction;

and the conduction control module 130 is configured to, after delaying the time of the time difference, control the vibration source to generate the second sound noise in a vibration manner based on the second waveform, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction manner, and then is superposed with the first sound noise conducted through air at the auditory nerve of the user and then is cancelled.

The device firstly acquires the first sound noise to obtain a first waveform of the first sound noise, then, a second waveform of a second sound noise having a phase opposite to that of the first sound noise is obtained by calculation, and at the same time, since the second sound noise needs to be conducted to the auditory nerve of the user by bone conduction to cancel the first sound noise conducted into the ear of the user through the air, while since the speed of sound conducted through bone conduction and through the air is different, it is necessary to calculate a time difference value based on the time when the second acoustic noise is conducted to the auditory nerve by bone conduction and the time when the first acoustic noise is conducted to the auditory nerve by air conduction, and controlling the vibration source to generate a second sound noise according to the time difference value, so that the second sound noise and the first sound noise arrive at the auditory nerve at the same time to be counteracted. Since the first acoustic noise conducted into the ear through the air and the calculated reverse noise (i.e., the second acoustic noise) of the first acoustic noise are directly added and cancelled, a good effect can be obtained in reducing or even eliminating the ambient noise conducted into the ear through the air.

In an embodiment of the present invention, the calculating module 120 includes a calculating sub-module, configured to calculate a second waveform of the second sound noise if the amplitude value of the first waveform is between a first preset value and a second preset value.

In this embodiment of the present invention, the calculating module 120 includes a first calculating sub-module, configured to transform the first waveform from a time domain to a frequency domain by using fourier transform, so as to obtain a frequency domain waveform of the first waveform; inverting the frequency domain waveform to obtain an inverted frequency domain waveform; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by using inverse Fourier transform to obtain a second waveform of the second sound noise.

In this embodiment of the present invention, the obtaining module 110 includes a first obtaining sub-module, configured to obtain a first sound noise around an auricle of a user, decompose the first sound noise to obtain a plurality of first sub-sound noises, and obtain a first sub-waveform corresponding to each of the first sub-sound noises; the calculating module 120 further includes a second calculating sub-module, configured to transform each of the first sub-waveforms from a time domain to a frequency domain by using fourier transform, so as to obtain a frequency domain sub-waveform of each of the first sub-waveforms; superposing the plurality of frequency domain sub-waveforms to obtain superposed frequency domain waveforms, and inverting the superposed frequency domain waveforms to obtain inverted frequency domain waveforms; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by adopting inverse Fourier transform to obtain a second waveform of the second sound noise.

It should be noted that, a noise reduction device for bone conduction headphones according to the third embodiment of the present invention and a noise reduction method for bone conduction headphones according to the method embodiment of the present invention are based on the same inventive concept, and the corresponding technical contents in the device embodiment and the method embodiment are applicable to each other, and will not be described in detail herein.

Example four

Fig. 8 illustrates a noise reduction system 200 for a bone conduction headset according to a fourth embodiment of the present invention, including: a microprocessor 210, a vibration source 220, and at least one sound sensor 230. The details are as follows:

the sound sensor 230 for collecting a first sound noise around the auricle of the user;

the microprocessor 210 is configured to obtain the first sound noise, obtain a first waveform of the first sound noise, and calculate a second waveform of a second sound noise based on the first waveform, where the second waveform and the first waveform have opposite phases corresponding to a same time point; calculating a time difference value based on a time at which the second sound noise is conducted to the auditory nerve of the user by bone conduction and a time at which the first sound noise is conducted to the auditory nerve of the user by air conduction; outputting a control signal based on the second waveform to the vibration source 220 after delaying the time of the time difference;

the vibration source 220 is configured to receive the control signal, and generate the second sound noise in a vibration manner based on the control signal, so that the second sound noise is transmitted to the auditory nerve of the user in a bone conduction manner, and then is superposed with the first sound noise transmitted through air at the auditory nerve of the user and then cancelled.

The system firstly acquires the first sound noise, obtains a first waveform of the first sound noise, then, a second waveform of a second sound noise having a phase opposite to that of the first sound noise is obtained by calculation, and at the same time, since the second sound noise needs to be conducted to the auditory nerve of the user by bone conduction to cancel the first sound noise conducted into the ear of the user through the air, while since the speed of sound conducted through bone conduction and through the air is different, it is necessary to calculate a time difference value based on the time when the second acoustic noise is conducted to the auditory nerve by bone conduction and the time when the first acoustic noise is conducted to the auditory nerve by air conduction, and controlling the vibration source to generate a second sound noise according to the time difference value, so that the second sound noise and the first sound noise arrive at the auditory nerve at the same time to be counteracted. Since the first acoustic noise conducted into the ear through the air and the calculated reverse noise (i.e., the second acoustic noise) of the first acoustic noise are directly added and cancelled, a good effect can be obtained in reducing or even eliminating the ambient noise conducted into the ear through the air.

In the embodiment of the present invention, the microprocessor 210 is further configured to calculate a second waveform of the second sound noise if the amplitude value of the first waveform is between a first preset value and a second preset value.

In this embodiment of the present invention, the microprocessor 210 is further configured to transform the first waveform from a time domain to a frequency domain by using fourier transform, so as to obtain a frequency domain waveform of the first waveform; inverting the frequency domain waveform to obtain an inverted frequency domain waveform; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by using inverse Fourier transform to obtain a second waveform of the second sound noise.

In this embodiment of the present invention, the microprocessor 210 is further configured to obtain a first sound noise around the auricle of the user, decompose the first sound noise to obtain a plurality of first sub-sound noises, and obtain a first sub-waveform corresponding to each of the first sub-sound noises; transforming each first sub-waveform from a time domain to a frequency domain by adopting Fourier transform to obtain a frequency domain sub-waveform of each first sub-waveform; superposing the plurality of frequency domain sub-waveforms to obtain superposed frequency domain waveforms, and inverting the superposed frequency domain waveforms to obtain inverted frequency domain waveforms; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by adopting inverse Fourier transform to obtain a second waveform of the second sound noise.

In the embodiment of the present invention, the system further includes a data storage module, configured to store data.

In the embodiment of the present invention, the system further includes an amplifying module, configured to amplify the first sound noise collected by the sound sensor 230, so as to analyze the amplified first sound noise, and determine a decibel value of the first sound noise.

It should be noted that, the noise reduction system for bone conduction headphones according to the fourth embodiment of the present invention and the noise reduction method for bone conduction headphones according to the method embodiment of the present invention are based on the same inventive concept, and the corresponding technical contents in the system embodiment and the method embodiment are applicable to each other, and will not be described in detail herein.

EXAMPLE five

Fig. 9 is a schematic diagram of a bone conduction headset according to still another embodiment of the present invention. The bone conduction headset 300 as shown in fig. 9 may include: a processor 310, a memory 320, and a computer program 330 stored in the memory 320 and executable on the processor 310. The steps in the above-described embodiments of the noise reduction method for bone conduction headphones are implemented when the computer program 330 is executed by the processor 310. The memory 320 is used to store a computer program comprising program instructions. The processor 310 is operative to execute program instructions stored in the memory 320. Wherein the processor 310 is configured to invoke the program instructions to perform the following operations:

the processor 310 is configured to obtain a first sound noise around an auricle of a user, obtain a first waveform of the first sound noise, and calculate a second waveform of a second sound noise based on the first waveform, where the second waveform has an opposite phase to a same time point on the first waveform.

The processor 310 is further configured to calculate a time difference based on a time at which the second acoustic noise is conducted to the auditory nerve of the user by bone conduction and a time at which the first acoustic noise is conducted to the auditory nerve of the user by air conduction.

The processor 310 is further configured to control the vibration source to generate the second sound noise in a vibration manner based on the second waveform after delaying the time of the time difference, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction manner and then is superposed with the first sound noise conducted through air at the auditory nerve of the user to be cancelled. The bone conduction earphone firstly acquires the first sound noise to obtain a first waveform of the first sound noise, then, a second waveform of a second sound noise having a phase opposite to that of the first sound noise is obtained by calculation, and at the same time, since the second sound noise needs to be conducted to the auditory nerve of the user by bone conduction to cancel the first sound noise conducted into the ear of the user through the air, while since the speed of sound conducted through bone conduction and through the air is different, it is necessary to calculate a time difference value based on the time when the second acoustic noise is conducted to the auditory nerve by bone conduction and the time when the first acoustic noise is conducted to the auditory nerve by air conduction, and controlling the vibration source to generate a second sound noise according to the time difference value, so that the second sound noise and the first sound noise arrive at the auditory nerve at the same time to be counteracted. Since the first acoustic noise conducted into the ear through the air and the calculated reverse noise (i.e., the second acoustic noise) of the first acoustic noise are directly added and cancelled, a good effect can be obtained in reducing or even eliminating the ambient noise conducted into the ear through the air.

Further, the processor 310 is further configured to calculate a second waveform of the second sound noise if the amplitude value of the first waveform is between a first preset value and a second preset value.

Specifically, the processor 310 is further configured to: transforming the first waveform from a time domain to a frequency domain by using Fourier transform to obtain a frequency domain waveform of the first waveform; inverting the frequency domain waveform to obtain an inverted frequency domain waveform; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by using inverse Fourier transform to obtain a second waveform of the second sound noise.

Specifically, the processor 310 is further configured to obtain a first sound noise around the auricle of the user, decompose the first sound noise to obtain a plurality of first sub-sound noises, and obtain a first sub-waveform corresponding to each of the first sub-sound noises; transforming each of the first sub-waveforms from the time domain to the frequency domain using a fourier transform to obtain frequency domain sub-waveforms of a plurality of the first sub-waveforms; superposing the plurality of frequency domain sub-waveforms to obtain superposed frequency domain waveforms, and inverting the superposed frequency domain waveforms to obtain inverted frequency domain waveforms; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by adopting inverse Fourier transform to obtain a second waveform of the second sound noise.

It should be understood that, in the embodiment of the present invention, the Processor 310 may be a Central Processing Unit (CPU), and the Processor 310 may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 320 may include both read-only memory and random access memory and provides instructions and data to the processor 310. A portion of memory 320 may also include non-volatile random access memory. For example, the memory 320 may also store device type information.

It should be noted that the bone conduction headset 300 may include, but is not limited to, a processor 310, a memory 320, and a computer program 330. Those skilled in the art will appreciate that fig. 9 is merely an example of the bone conduction headset 300 and does not constitute a limitation of the bone conduction headset 300, that the bone conduction headset 300 may include more or less components than those shown, or some components may be combined, or different components, for example, that the bone conduction headset 300 may further include a sound sensor for collecting a first sound noise around the pinna of the user, a vibration source, etc.; the vibration source is configured to receive the control signal sent by the processor 310, and generate the second sound noise in a vibration manner based on the control signal, so that the second sound noise is transmitted to the auditory nerve of the user in a bone conduction manner, and then is superposed with the first sound noise transmitted through air at the auditory nerve of the user and then cancelled.

It should be noted that the bone conduction headset proposed in the fifth embodiment of the present invention and the noise reduction method for the bone conduction headset proposed in the method embodiment of the present invention are based on the same inventive concept, and the corresponding technical contents in the device embodiment and the method embodiment are applicable to each other, and are not described in detail herein.

EXAMPLE six

In another embodiment of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program comprising program instructions that when executed by a processor implement:

acquiring first sound noise around a user auricle, acquiring a first waveform of the first sound noise, and calculating a second waveform of second sound noise based on the first waveform, wherein the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point;

calculating a time difference value based on a time at which the second sound noise is conducted to the auditory nerve of the user by bone conduction and a time at which the first sound noise is conducted to the auditory nerve of the user by air conduction;

and after delaying the time of the time difference, controlling a vibration source to generate the second sound noise in a vibration mode based on the second waveform, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then is superposed with the first sound noise conducted through air at the auditory nerve of the user and then is counteracted.

The computer readable storage medium first acquires the first sound noise, obtains a first waveform of the first sound noise, then, a second waveform of a second sound noise having a phase opposite to that of the first sound noise is obtained by calculation, and at the same time, since the second sound noise needs to be conducted to the auditory nerve of the user by bone conduction to cancel the first sound noise conducted into the ear of the user through the air, while since the speed of sound conducted through bone conduction and through the air is different, it is necessary to calculate a time difference value based on the time when the second acoustic noise is conducted to the auditory nerve by bone conduction and the time when the first acoustic noise is conducted to the auditory nerve by air conduction, and controlling the vibration source to generate a second sound noise according to the time difference value, so that the second sound noise and the first sound noise arrive at the auditory nerve at the same time to be counteracted. Since the first acoustic noise conducted into the ear through the air and the calculated reverse noise (i.e., the second acoustic noise) of the first acoustic noise are directly added and cancelled, a good effect can be obtained in reducing or even eliminating the ambient noise conducted into the ear through the air.

Further, the computer program when executed by the processor further implements:

and if the amplitude value of the first waveform is between a first preset value and a second preset value, calculating a second waveform of the second sound noise.

In particular, the computer program when executed by a processor further implements:

transforming the first waveform from a time domain to a frequency domain by using Fourier transform to obtain a frequency domain waveform of the first waveform; inverting the frequency domain waveform to obtain an inverted frequency domain waveform; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by using inverse Fourier transform to obtain a second waveform of the second sound noise.

acquiring first sound noise around a user auricle, decomposing the first sound noise to obtain a plurality of first sub-sound noises, and obtaining a first sub-waveform corresponding to each first sub-sound noise; transforming each first sub-waveform from a time domain to a frequency domain by adopting Fourier transform to obtain a frequency domain sub-waveform of each first sub-waveform; superposing a plurality of frequency domain waveforms to obtain superposed frequency domain waveforms, and inverting the superposed frequency domain waveforms to obtain inverted frequency domain waveforms; and transforming the inverse frequency domain waveform from the frequency domain to the time domain by adopting inverse Fourier transform to obtain a second waveform of the second sound noise.

The computer readable storage medium may be an internal storage unit of the device according to any of the foregoing embodiments, for example, a hard disk or a memory of the device. The computer readable storage medium may also be an external storage device of the device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the device. Further, the computer-readable storage medium may also include both an internal storage unit and an external storage device of the apparatus. The computer-readable storage medium is used for storing the computer program and other programs and data required by the apparatus. The computer readable storage medium may also be used to temporarily store data that has been output or is to be output.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiments provided in the present invention, it should be understood that the disclosed method, apparatus, and terminal may be implemented in other ways. For example, the above-described method, apparatus and terminal embodiments are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implemented, for example, multiple units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow of the method according to the embodiments of the present invention may also be implemented by a computer program, which may be stored in a computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method embodiments may be implemented. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, etc. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media does not include electrical carrier signals and telecommunications signals as is required by legislation and patent practice.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

Claims

1. A noise reduction method for a bone conduction headset, comprising:

after delaying the time of the time difference, controlling a vibration source to generate the second sound noise in a vibration mode based on the second waveform, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then is superposed with the first sound noise conducted through air at the auditory nerve of the user and then is counteracted;

wherein said calculating a second waveform of a second sound noise based on said first waveform comprises:

and calculating a second waveform of the second sound noise only if the amplitude value of the first waveform is between a first preset value and a second preset value, wherein the first preset value and the second preset value are different in size.

2. The noise reduction method according to claim 1, wherein the calculating a second waveform of second sound noise based on the first waveform comprises:

transforming the first waveform from a time domain to a frequency domain by using Fourier transform to obtain a frequency domain waveform of the first waveform;

inverting the frequency domain waveform to obtain an inverted frequency domain waveform;

and transforming the inverse frequency domain waveform from the frequency domain to the time domain by using inverse Fourier transform to obtain a second waveform of the second sound noise.

3. The noise reduction method according to claim 1, wherein the obtaining a first acoustic noise around a pinna of a user to obtain a first waveform of the first acoustic noise comprises: acquiring first sound noise around a user auricle, decomposing the first sound noise to obtain a plurality of first sub-sound noises, and obtaining a first sub-waveform corresponding to each first sub-sound noise;

correspondingly, the calculating a second waveform of a second sound noise based on the first waveform comprises:

transforming each first sub-waveform from a time domain to a frequency domain by using Fourier transform to obtain a frequency domain sub-waveform of each first sub-waveform;

superposing the plurality of frequency domain sub-waveforms to obtain superposed frequency domain waveforms, and inverting the superposed frequency domain waveforms to obtain inverted frequency domain waveforms;

and transforming the inverse frequency domain waveform from the frequency domain to the time domain by adopting inverse Fourier transform to obtain a second waveform of the second sound noise.

4. A bone conduction headset comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of claims 1 to 3 when executing the computer program.

5. A noise reduction device for a bone conduction headset, comprising:

the device comprises an acquisition module, a processing module and a processing module, wherein the acquisition module is used for acquiring first sound noise around the auricle of a user, acquiring a first waveform of the first sound noise, and calculating a second waveform of second sound noise based on the first waveform, and the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point;

a calculation module, configured to calculate a time difference value based on a time when the second sound noise is conducted to the auditory nerve of the user in a bone conduction manner and a time when the first sound noise is conducted to the auditory nerve of the user in an air conduction manner;

the conduction control module is used for controlling the vibration source to generate the second sound noise in a vibration mode based on the second waveform after delaying the time of the time difference value, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then superposed with the first sound noise conducted through air at the auditory nerve of the user to be offset;

the calculation module comprises a calculation submodule and is used for calculating a second waveform of second sound noise only when the amplitude value of the first waveform is between a first preset value and a second preset value, and the first preset value and the second preset value are different in size.

6. A noise reduction system for a bone conduction headset comprising a microprocessor, a vibration source and at least one sound sensor;

the sound sensor is used for collecting first sound noise around the auricle of the user;

the microprocessor is used for acquiring the first sound noise, obtaining a first waveform of the first sound noise, and calculating a second waveform of a second sound noise based on the first waveform, wherein the phase of the second waveform is opposite to that of the first waveform corresponding to the same time point; calculating a time difference value based on a time at which the second sound noise is conducted to the auditory nerve of the user by bone conduction and a time at which the first sound noise is conducted to the auditory nerve of the user by air conduction; outputting a control signal based on the second waveform to the vibration source after delaying the time of the time difference;

the vibration source is used for receiving the control signal and generating the second sound noise in a vibration mode based on the control signal, so that the second sound noise is conducted to the auditory nerve of the user in a bone conduction mode and then is superposed with the first sound noise conducted through the air at the auditory nerve of the user and then is counteracted;

the microprocessor is further configured to calculate a second waveform of the second sound noise only if the amplitude value of the first waveform is between a first preset value and a second preset value, where the first preset value and the second preset value are different in size.

7. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 3.