CN113643682A

CN113643682A - Noise reduction method, chip module and equipment

Info

Publication number: CN113643682A
Application number: CN202111189551.3A
Authority: CN
Inventors: 魏孜宸; 方思敏
Original assignee: Spreadtrum Communications Shanghai Co Ltd
Current assignee: Spreadtrum Communications Shanghai Co Ltd
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2021-11-12
Anticipated expiration: 2041-10-13
Also published as: CN113643682B; WO2023060793A1

Abstract

The embodiment of the application provides a noise reduction method, a chip module and equipment, wherein the noise reduction method comprises the following steps: performing narrow-band filtering processing on the first noise signal by using a narrow-band filter to obtain a first narrow-band signal, wherein the first noise signal is obtained after collecting environmental noise at the current moment; filtering the first noise signal by adopting a first filter to obtain a first broadband filtering signal; filtering the first narrow-band signal by using a second filter to obtain a first narrow-band filtered signal; and performing noise reduction processing on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal. The noise reduction method, the chip module and the equipment provided by the embodiment of the application can be used for improving the effect of noise reduction treatment on environmental noise.

Description

Noise reduction method, chip module and equipment

Technical Field

The embodiment of the application relates to the technical field of noise reduction, in particular to a noise reduction method, a chip module and equipment.

Background

At present, in order to improve the audio playing quality of a playing device (such as an earphone or a sound box), it is generally necessary to perform noise reduction processing on the environmental noise collected by the playing device.

In the related art, a method of performing noise reduction processing on ambient noise includes: usually, a vibration sensor is adopted to collect environmental noise to obtain the frequency and amplitude of narrow-band noise, the narrow-band noise is constructed according to the frequency and amplitude, a notch filtering method is adopted to perform noise reduction processing on the narrow-band noise, and then noise reduction processing is performed on the environmental noise according to the narrow-band noise after the noise reduction processing.

In the above process, the constructed narrow-band noise is prone to generate a large delay and a phase shift, resulting in a poor effect of performing noise reduction processing on the environmental noise.

Disclosure of Invention

The embodiment of the application provides a noise reduction method, a chip module and equipment, which are used for improving the effect of noise reduction treatment on environmental noise.

In a first aspect, an embodiment of the present application provides a noise reduction method, where the method includes:

performing narrow-band filtering processing on the first noise signal by using a narrow-band filter to obtain a first narrow-band signal, wherein the first noise signal is obtained after collecting environmental noise at the current moment;

filtering the first noise signal by adopting a first filter to obtain a first broadband filtering signal; filtering the first narrow-band signal by using a second filter to obtain a first narrow-band filtered signal;

and performing noise reduction processing on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal.

In one possible design, the filtering the first noise signal with the first filter to obtain the first wideband filtered signal includes:

acquiring a second signal obtained by carrying out noise reduction processing on a second noise signal acquired at the previous moment;

determining the working parameters of the first filter at the current moment according to the second signal, the working parameters of the first filter at the last moment and the first noise signal;

and according to the working parameters of the first filter at the current moment, filtering the first noise signal to obtain a first broadband filtering signal.

In one possible design, determining the operating parameter of the first filter at the current time based on the second signal, the operating parameter of the first filter at the previous time, and the first noise signal includes:

estimating the second signal by adopting a preset estimation model, and determining a parameter adjustment step length;

acquiring a third noise signal after the first noise signal is transmitted through the first transmission channel; the first transmission channel is a transmission channel between a reference microphone and a first filter, wherein the reference microphone acquires a first noise signal;

and determining the difference value of the product of the working parameter of the first filter at the last moment and the preset value, the parameter adjusting step length, the second signal and the third noise signal as the working parameter of the first filter at the current moment.

In one possible design, obtaining a third noise signal after passing the first noise signal through the first transmission channel includes:

and determining the product of the first channel transfer function corresponding to the first transmission channel and the first noise signal as a third noise signal.

In one possible design, the filtering the first narrowband signal with the second filter to obtain a first narrowband filtered signal includes:

determining the working parameters of the second filter at the current moment according to the second signal, the working parameters of the second filter at the last moment and the first narrow-band signal;

and according to the working parameters of the second filter at the current moment, filtering the first narrow-band signal to obtain a first narrow-band filtering signal.

In one possible design, determining the operating parameter of the second filter at the current time based on the second signal, the operating parameter of the second filter at the previous time, and the first narrowband signal includes:

obtaining a second narrowband signal after passing the first narrowband signal through a second transmission channel; the second transmission channel is a transmission channel between the narrow-band filter and the second filter;

and determining the difference value of the working parameter of the second filter at the last moment and the product of the preset value, the parameter adjusting step length and the second signal and the second narrow-band signal as the working parameter of the second filter at the current moment.

In one possible design, performing noise reduction processing on the first noise signal according to the first wideband filtered signal and the first narrowband filtered signal includes:

acquiring a fourth noise signal after the first noise signal is transmitted through a third transmission channel, wherein the third transmission channel is a transmission channel between the reference microphone and the loudspeaker;

the fourth noise signal is superimposed with the first wideband filtered signal and the first narrowband filtered signal.

In a second aspect, the present application provides a noise reduction chip, including: the device comprises a reference microphone, a first filter, a narrow-band filter, a second filter and a first adder, wherein the reference microphone is respectively connected with the first filter, the narrow-band filter and the first adder, the narrow-band filter is also connected with the second filter, and the first filter and the second filter are also respectively connected with the first adder;

the reference microphone is used for collecting environmental noise to obtain a first noise signal;

the narrow-band filter is used for carrying out narrow-band filtering processing on the first noise signal to obtain a first narrow-band signal;

the first filter is used for carrying out filtering processing on the first noise signal to obtain a first broadband filtering signal;

the second filter is used for carrying out filtering processing on the first narrow-band signal to obtain a first narrow-band filtering signal;

and the first adder is used for carrying out noise reduction processing on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal.

In one possible design, the chip further includes: the loudspeaker is connected with the first adder, and the error microphone is respectively connected with the first filter and the second filter;

the first adder is also used for carrying out noise reduction processing on the second noise signal to obtain a second signal;

a speaker for playing the second signal;

and the error microphone is used for acquiring the second signal.

In a third aspect, an embodiment of the present application provides a noise reduction apparatus, including: the device comprises a first filtering module, a second filtering module, a third filtering module and a noise reduction module; wherein the content of the first and second substances,

the first filtering module is used for carrying out narrow-band filtering processing on the first noise signal to obtain a first narrow-band signal, and the first noise signal is obtained after the environmental noise at the current moment is collected;

the second filtering module is used for filtering the first noise signal to obtain a first broadband filtering signal;

the third filtering module is used for filtering the first narrow-band signal to obtain a first narrow-band filtering signal;

and the noise reduction module is used for carrying out noise reduction processing on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal.

In one possible design, the second filtering module is specifically configured to:

In one possible design, the third filtering module is specifically configured to:

In one possible design, the noise reduction module is specifically configured to:

In a fourth aspect, an embodiment of the present application provides a noise reduction apparatus, including: a processor and a memory;

the memory stores computer-executable instructions;

the processor executes the computer-executable instructions stored by the memory, causing the processor to perform the noise reduction method of any of the first aspects.

In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, where computer-executable instructions are stored, and when a processor executes the computer-executable instructions, the noise reduction method according to any one of the first aspect is implemented.

In a sixth aspect, the present application provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, the noise reduction method according to any one of the first aspect is implemented.

The embodiment of the application provides a noise reduction method, a chip module and equipment, wherein the noise reduction method comprises the following steps: performing narrow-band filtering processing on the first noise signal by using a narrow-band filter to obtain a first narrow-band signal, wherein the first noise signal is obtained after collecting environmental noise at the current moment; filtering the first noise signal by adopting a first filter to obtain a first broadband filtering signal; filtering the first narrow-band signal by using a second filter to obtain a first narrow-band filtered signal; and performing noise reduction processing on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal. The embodiment of the application provides a noise reduction method, a chip module and equipment, which can be used for improving the effect of noise reduction treatment on environmental noise.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to the drawings without inventive exercise.

Fig. 1 is a first flowchart of a noise reduction method provided in an example of the present application;

fig. 2 is a second flowchart of a noise reduction method provided in the embodiment of the present application;

fig. 3 is a first schematic structural diagram of a noise reduction chip according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a noise reduction chip provided in the embodiment of the present application;

fig. 5 is a schematic structural diagram of a noise reduction chip provided in the embodiment of the present application;

FIG. 6 is a schematic diagram of a noise reduction method according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a noise reduction device according to an embodiment of the present application;

fig. 8 is a schematic diagram of a hardware structure of a noise reduction device according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In practical applications, when a user uses a wearable playback device (e.g., an earphone or a sound box) to play audio, the played audio is interfered by environmental noise in an environment where the playback device is located, so that the audio playback quality of the playback device is poor. Therefore, in order to improve the audio playing quality of the playing device, it is generally necessary to perform noise reduction processing on the ambient noise.

In the related art, filtering processing is performed on environmental noise according to the narrow-band noise after noise reduction processing, the narrow-band noise needs to be constructed according to frequency and amplitude, and because the method for constructing the narrow-band noise according to the frequency and the amplitude is complex and the processing time required for constructing the narrow-band noise is long, the constructed narrow-band noise is prone to generate large delay and phase offset, and the effect of performing noise reduction processing on the environmental noise is poor.

In the present application, in order to improve the effect of noise reduction processing on environmental noise, the inventors thought that: the narrow-band filter is adopted to carry out narrow-band filtering processing on the first noise signal to obtain the first narrow-band signal, so that the method for obtaining the narrow-band signal can be simplified, the processing time for obtaining the narrow-band signal is shortened, the narrow-band signal is prevented from having larger time delay and phase deviation, and the effect of carrying out noise reduction processing on the environmental noise can be improved.

The technical solution of the present application will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Fig. 1 is a first flowchart of a noise reduction method provided in an example of the present application. As shown in fig. 1, the method includes:

s101, narrow-band filtering processing is carried out on the first noise signal by adopting a narrow-band filter to obtain a first narrow-band signal.

Optionally, the execution main body in the embodiment of the present application may be a noise reduction device, or a noise reduction chip in the noise reduction device, or a noise reduction chip module in the noise reduction device. The noise reduction device, the noise reduction chip and the noise reduction chip module can be realized by the combination of software and/or hardware.

Optionally, the noise reduction device may be any device that needs to perform noise reduction processing on ambient noise, such as a headset, a sound box, a wearable device, a noise reduction device in an automobile, and the like.

The first noise signal is obtained after collecting the environmental noise at the current moment.

The environmental noise is the environmental noise in the environment where the noise reduction equipment, the noise reduction chip or the noise reduction chip module is located.

S102, filtering the first noise signal by using a first filter to obtain a first broadband filtering signal; and filtering the first narrow-band signal by adopting a second filter to obtain a first narrow-band filtered signal.

The first filter and the second filter are Active Noise Control (ANC) filters.

Specifically, before the first broadband filtering signal is obtained, the working parameter of the first filter at the current moment is determined, and then the first noise signal is filtered according to the working parameter of the first filter at the current moment to obtain the first broadband filtering signal.

The method for determining the operating parameter of the first filter at the current moment may include: acquiring a second signal obtained by carrying out noise reduction processing on a second noise signal acquired at the previous moment; and determining the working parameters of the first filter at the current moment according to the second signal, the working parameters of the first filter at the last moment and the first noise signal. Specifically, please refer to S202-S206 in FIG. 2.

Specifically, before the first narrow-band filtering signal is obtained by filtering the first narrow-band signal with the second filter, the working parameter of the second filter at the current moment needs to be determined, and the first narrow-band signal is filtered according to the working parameter of the second filter at the current moment, so that the first narrow-band filtering signal is obtained.

The method for determining the working parameters of the second filter at the current moment comprises the following steps: acquiring a second signal obtained by carrying out noise reduction processing on a second noise signal acquired at the previous moment; and determining the working parameters of the second filter at the current moment according to the second signal, the working parameters of the second filter at the last moment and the first narrow-band signal. Specifically, please refer to S207-S212 in FIG. 2.

S103, carrying out noise reduction processing on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal.

Specifically, a fourth noise signal after the first noise signal is transmitted through the third transmission channel is acquired; the fourth noise signal is superimposed with the first wideband filtered signal and the first narrowband filtered signal.

The third transmission channel is a transmission channel between the reference microphone and the speaker, and is also equivalent to a transmission channel between the reference microphone and the first adder, as shown in fig. 3 to 5.

Acquiring a fourth noise signal after the first noise signal is transmitted through the third transmission channel, including: the fourth noise signal is determined as the product of the third channel transfer function (e.g., S3(z) in fig. 6) corresponding to the third transmission channel and the first noise signal.

Because the amplitude of the first broadband filtering signal and the amplitude of the first narrowband filtering signal are opposite to the amplitude of the fourth noise signal, the fourth noise signal is superposed with the first broadband filtering signal and the first narrowband filtering signal, the broadband filtering signal and the narrowband filtering signal in the fourth noise signal can be offset, and therefore noise reduction processing of the first noise signal is achieved, and noise reduction processing of the environmental noise is further achieved.

The narrow-band filter is adopted to carry out narrow-band filtering processing on the first noise signal to obtain the first narrow-band signal, so that the first narrow-band signal can be prevented from being delayed for a long time and generating phase deviation, and the effect of carrying out noise reduction processing on the environmental noise is improved.

Different from the prior art, in the prior art, a microphone is generally adopted to collect environmental noise to obtain broadband noise, and the broadband noise is subjected to noise reduction processing through a self-adaptive filter; usually, a vibration sensor is adopted to collect environmental noise to obtain the frequency and amplitude of narrow-band noise, the narrow-band noise is constructed according to the frequency and the amplitude, a notch filtering method is adopted to perform noise reduction processing on the narrow-band noise, and then filtering processing is performed on the wide-band noise according to the wide-band noise and the narrow-band noise after the noise reduction processing, so that the noise reduction processing on the environmental noise is realized. In the above related art, the method for constructing the narrowband noise according to the frequency and the amplitude is complex, and the constructed narrowband noise is prone to generate a large delay and a phase shift, so that the effect of performing noise reduction processing on the environmental noise is poor. In the noise reduction method provided in the embodiment of fig. 1, the narrowband filter is used to perform narrowband filtering processing on the first noise signal to obtain the first narrowband signal, and the narrowband signal can be obtained relatively easily.

When the noise reduction device is a device in an automobile. Unlike the prior art, in the prior art, a feedback ANC system in the device filters broadband noise and narrowband noise by using a mixed filtering method of a feedforward filter and a feedback filter, wherein the feedback filter causes that the middle and high frequency band noise is easy to generate a 'water bed effect' without reduction and increase, thereby causing the overall filtering effect to be poor. In the application, the second filter (namely, the feedforward ANC filter) is adopted to filter the first narrow-band signal, so that a feedback filter is not used, the 'water bed effect' is suppressed, and the effect of noise reduction on the environmental noise is improved.

On the basis of the above embodiments, the noise reduction method provided by the present application is further described in detail below with reference to fig. 2. Specifically, please refer to fig. 2.

Fig. 2 is a second flowchart of a noise reduction method according to an embodiment of the present application. As shown in fig. 2, the method includes:

s201, narrow-band filtering processing is carried out on the first noise signal by adopting a narrow-band filter, and a first narrow-band signal is obtained.

Specifically, the execution method of S201 is the same as the execution method of S101, and the execution process of S202 is not described herein again.

S202, acquiring a second signal obtained by carrying out noise reduction processing on a second noise signal acquired at the previous moment.

The second noise signal is obtained by collecting the environmental noise at the previous moment.

The method for performing noise reduction processing on the second noise signal acquired at the previous time is similar to the method for performing noise reduction processing on the first noise signal acquired at the current time, and is not described herein again.

And S203, estimating the second signal by adopting a preset estimation model, and determining a parameter adjustment step length.

The preset estimation model may be a Least Mean square algorithm (Least Mean square) model.

S204, acquiring a third noise signal after the first noise signal is transmitted through the first transmission channel.

The first transmission channel is a transmission channel between a reference microphone and a first filter, wherein the reference microphone acquires a first noise signal.

Specifically, the product of the first channel transfer function (e.g., S1(z) in fig. 6) corresponding to the first transmission channel and the first noise signal is determined as the third noise signal.

S205, determining the difference value of the product of the working parameter of the first filter at the previous moment and the preset value, the parameter adjusting step length, the second signal and the third noise signal as the working parameter of the first filter at the current moment.

Specifically, the operating parameter of the first filter at the current time can be determined by the following formula 1.

Formula 1;

wherein the content of the first and second substances,

for the operating parameters of the first filter at the current time instant n,

the operating parameter of the first filter at the last instant n-1,

in order to be a preset value, the device is provided with a power supply,

the step size is adjusted for the parameters,

in order to be able to generate the second signal,

is the third noise signal.

Wherein the content of the first and second substances,

wherein N is the total time.

Wherein the content of the first and second substances,

。

s206, filtering the first noise signal according to the working parameters of the first filter at the current moment to obtain a first broadband filtering signal.

And S207, acquiring a second signal obtained by carrying out noise reduction processing on the second noise signal acquired at the previous moment.

And S208, estimating the second signal by adopting a preset estimation model, and determining the parameter adjustment step length.

Specifically, the execution methods of S207 to S208 are the same as the execution methods of S202 to S203.

Alternatively, the methods shown in S207-S208 may not be performed in practical applications.

And S209, acquiring a second narrow-band signal after the first narrow-band signal is transmitted through a second transmission channel.

The second transmission path is a transmission path between the narrow band filter and the second filter.

Specifically, the second transmission channel transfers the product of the corresponding second channel transfer function (e.g., S2(z) in fig. 6) and the first narrowband signal, and is determined as the second narrowband signal.

S210, determining the difference value of the working parameter of the second filter at the previous moment and the product of the preset value, the parameter adjusting step length and the second signal and the second narrow-band signal as the working parameter of the second filter at the current moment.

Specifically, the operating parameter of the second filter at the current time can be determined by the following formula 2.

Formula 2;

wherein the content of the first and second substances,

for the operating parameters of the second filter at the current time instant n,

the operating parameter of the second filter at the last instant n-1,

in order to be a preset value, the device is provided with a power supply,

the step size is adjusted for the parameters,

in order to be able to generate the second signal,

is a second narrowband signal.

Wherein the content of the first and second substances,

。

wherein the content of the first and second substances,

。

and S211, filtering the first narrow-band signal according to the working parameters of the second filter at the current moment to obtain a first narrow-band filtering signal.

S212, noise reduction processing is carried out on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal.

Specifically, the execution method of S212 is the same as the execution method of S103, and the execution process of S212 is not described herein again.

In the noise reduction method provided in the embodiment of fig. 2, firstly, the working parameters of the first filter at the current time are determined through methods S202 to S205, and the first noise signal is filtered according to the working parameters of the first filter at the current time to obtain a first broadband filtering signal, so that the accuracy of the obtained first broadband filtering signal can be improved; secondly, determining the working parameters of the second filter at the current moment by the methods of S207-S210, and carrying out filtering processing on the first narrow-band signal according to the working parameters of the second filter at the current moment to obtain a first narrow-band filtering signal, so that the accuracy of the obtained first narrow-band filtering signal can be improved; in addition, the narrow-band filter is adopted to carry out narrow-band filtering processing on the first noise signal to obtain the first narrow-band signal, so that the first narrow-band signal can be prevented from being delayed for a long time and generating phase deviation, and the effect of carrying out noise reduction processing on the environmental noise is improved.

Further, in the present application, since a transmission channel usually causes signal attenuation when transmitting a signal, in order to improve accuracy of a signal received by a filter in the present application, a product of a first channel transfer function corresponding to a first transmission channel and a first noise signal is determined as a third noise signal, accuracy of obtaining the third noise signal is improved, a product of a second channel transfer function corresponding to a second transmission channel transfer and the first narrowband signal is determined as a second narrowband signal, accuracy of obtaining the second narrowband signal is improved, a product of a third channel transfer function corresponding to the third transmission channel and the first noise signal is determined as a fourth noise signal, and accuracy of obtaining the fourth noise signal is improved.

On the basis of the foregoing embodiment, the present application further provides a noise reduction chip, which is used for executing the noise reduction method in fig. 1 or fig. 2, and the following describes the noise reduction chip provided in the present application in further detail with reference to fig. 3.

Fig. 3 is a first schematic structural diagram of a noise reduction chip according to an embodiment of the present application. As shown in fig. 3, the noise reduction chip 30 includes: a reference microphone 31, a first filter 32, a narrow band filter 33, a second filter 34 and a first adder 35. The reference microphone 31 is connected to the first filter 32, the narrow-band filter 33, and the first adder 35, respectively, the narrow-band filter 33 is further connected to the second filter 34, and the first filter 32 and the second filter 34 are further connected to the first adder 35, respectively.

The noise reduction chip shown in fig. 3 may perform the noise reduction method shown in fig. 1 and 2. Specifically, when the noise reduction chip shown in fig. 3 executes the noise reduction method shown in fig. 1, the reference microphone 31 is used for collecting the environmental noise to obtain a first noise signal; a narrow-band filter 33, configured to perform narrow-band filtering processing on the first noise signal to obtain a first narrow-band signal; a first filter 32, configured to perform filtering processing on the first noise signal to obtain a first wideband filtering signal; a second filter 34, configured to perform filtering processing on the first narrowband signal to obtain a first narrowband filtered signal; a first adder 35, configured to perform noise reduction processing on the first noise signal according to the first wideband filtered signal and the first narrowband filtered signal.

Optionally, a second adder 40 may be further included in the noise reduction chip 30, and the second adder 40 is connected to the first filter 32, the second filter 34, and the first adder 35, respectively.

When the second adder 40 is included in the noise reduction chip 30, the second adder 40 is configured to add the first wideband filtered signal and the first narrowband filtered signal. The first adder 35 is configured to superimpose the first noise signal with the first wideband filtering signal and the first narrowband filtering signal, so as to cancel the wideband filtering signal and the narrowband filtering signal in the first noise signal according to the first wideband filtering signal and the first narrowband filtering signal, thereby implementing noise reduction processing on the first noise signal.

The implementation principle and the beneficial effect of the noise reduction chip provided in the embodiment of fig. 3 in the present application are similar to those of the technical solution shown in the embodiment of the method described above, and are not described here again.

Fig. 4 is a schematic structural diagram of a noise reduction chip according to an embodiment of the present application. On the basis of fig. 3, as shown in fig. 4, the noise reduction chip 30 further includes: a speaker 36 and an error microphone 37.

The speaker 36 is connected to the first adder 35, and the error microphone 37 is connected to the first filter 32 and the second filter 34, respectively.

The first adder 35 is further configured to perform noise reduction processing on the second noise signal to obtain a second signal.

A speaker 36 for playing the second signal.

And an error microphone 37 for acquiring the second signal.

The noise reduction chip shown in fig. 4 may perform the noise reduction methods shown in fig. 1 and 2. Specifically, when the noise reduction chip shown in fig. 4 executes the noise reduction method shown in fig. 2, the narrow band filter 33 is used to execute S201, the first adder 35, the speaker 36 and the error microphone 37 are used to execute S202 and S207, the first filter 32 is used to execute S203 to S206, the second filter 34 is used to execute S208 to S211, and the first adder 35 is used to execute S212.

The implementation principle and the beneficial effect of the noise reduction chip provided in the embodiment of fig. 4 in the present application are similar to those of the technical solution shown in the embodiment of the method described above, and are not described here again.

Fig. 5 is a third schematic structural diagram of a noise reduction chip provided in the embodiment of the present application. On the basis of fig. 4, as shown in fig. 5, the noise reduction chip 30 further includes: a first switch 38 and/or a second switch 39.

The first switch 38 is connected between the first filter 32 and the first adder 35.

The second switch 39 is connected between the second filter 34 and the first adder 35.

The first switch 38 and the second switch 39 may be hardware switches that can be operated by a user, and may be software switches that can be controlled by software.

The methods of fig. 1 and 2 described above may be performed when the first switch 38 and the second switch 39 are closed.

When the first switch 38 is closed and the second switch 39 is open, only: filtering the first noise signal by adopting a first filter to obtain a first broadband filtering signal; and performing noise reduction processing on the first noise signal according to the first broadband filtering signal.

When the first switch 38 is open and the second switch 39 is closed, only: performing narrow-band filtering processing on the first noise signal by using a narrow-band filter to obtain a first narrow-band signal; filtering the first narrow-band signal by using a second filter to obtain a first narrow-band filtered signal; and performing noise reduction processing on the first noise signal according to the first broadband filtering signal and the first narrow-band filtering signal.

The noise reduction chip shown in fig. 5 further includes: a first switch 38 and/or a second switch 39. The first switch 38 and/or the second switch 39 can enable a user to flexibly select a method for performing noise reduction processing on the first noise signal, so that flexibility of performing noise reduction processing on the first noise signal is improved.

The embodiment of the present application further provides a chip module of making an uproar falls, includes: the noise reduction chip is provided.

An embodiment of the present application further provides a noise reduction device, including: the noise reduction chip or the noise reduction chip module is provided.

Optionally, in this application, the noise reduction chip may be an earphone chip, a wearable noise reduction chip, an automobile noise reduction chip, or other various noise reduction chips.

In the noise reduction chip provided by the figure application, the narrow-band filtering part (comprising the narrow-band filter and the second filter) can be multiplexed with the wide-band filtering part (comprising the narrow-band filter and the second filter), so that the area of the noise reduction chip can be saved. In addition, the noise reduction chip comprises the reference microphone 31, the first filter 32, the narrow-band filter 33, the second filter 34 and the first adder 35 to realize the noise reduction method, so that the realization process of the noise reduction chip is simpler.

When the noise reduction chip is an automobile noise reduction chip, the frequency and the amplitude of narrow-band noise acquired by a non-acoustic sensor (such as a vibration sensor) can be avoided, the construction process of the narrow-band noise is avoided, and the design structure of the automobile noise reduction chip is simplified.

Fig. 6 is a schematic diagram of a noise reduction method according to an embodiment of the present application. For example, on the basis of fig. 5, as shown in fig. 6, the method includes: x (n), p (z), W1(z), k1, S1(z), LMS, narrow band filter, W2(z), k2, S2(z), LMS.

x (n) represents a first noise signal, namely a broadband noise signal obtained after the reference microphone collects the environmental noise.

P (z) represents the acoustic response of the first noise signal from the reference microphone to the human ear, i.e. corresponding to the third channel transfer function.

W1(z) denotes a first filter.

k1 denotes a first switch.

S1(z) represents the first channel transfer function.

LMS represents an LMS algorithm model for adjusting the operating parameters of the first filter and the second filter.

W2(z) denotes a second filter.

k2 denotes a second switch.

S2(z) represents the second channel transfer function.

S3(z) is a fourth channel transfer function of a fourth transmission channel between the first summer and the error microphone. S1(z) and S2(z) are estimated from S3(z), respectively.

e (n) is the first signal after the noise reduction processing is performed on the first noise signal. The first signal is a signal acquired by an error microphone when the loudspeaker plays the first signal.

In practical applications, the product of the signal played by the loudspeaker and the transfer function of the fourth channel is equal to e (n).

Fig. 7 is a schematic structural diagram of a noise reduction device according to an embodiment of the present application. As shown in fig. 7, the noise reducing device 70 includes: a first filtering module 701, a second filtering module 702, a third filtering module 703 and a noise reduction module 704; wherein the content of the first and second substances,

the first filtering module 701 is configured to perform narrow-band filtering processing on a first noise signal to obtain a first narrow-band signal, where the first noise signal is obtained by collecting environmental noise at a current time;

a second filtering module 702, configured to perform filtering processing on the first noise signal to obtain a first wideband filtering signal;

a third filtering module 703, configured to perform filtering processing on the first narrowband signal to obtain a first narrowband filtered signal;

and a noise reduction module 704, configured to perform noise reduction processing on the first noise signal according to the first wideband filtered signal and the first narrowband filtered signal.

The noise reduction apparatus 70 provided in the embodiment of the present application may implement the technical solution shown in the above method embodiment, and the implementation principle and the beneficial effect are similar, which are not described herein again.

In one possible design, the second filtering module 702 is specifically configured to:

In one possible design, the third filtering module 703 is specifically configured to:

In one possible design, noise reduction module 704 is specifically configured to:

Fig. 8 is a schematic diagram of a hardware structure of a noise reduction device according to an embodiment of the present application. As shown in fig. 8, the noise reduction apparatus 80 includes: a processor 801 and a memory 802,

the processor 801 and the memory 802 are connected by a bus 803.

In particular implementations, the processor 801 executes computer-executable instructions stored by the memory 802, causing the processor 801 to perform the noise reduction methods as described above.

For a specific implementation process of the processor 801, reference may be made to the above method embodiments, which have similar implementation principles and technical effects, and details of this embodiment are not described herein again.

In the embodiment shown in fig. 8, it should be understood that the Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in the incorporated application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor.

The memory may comprise high speed RAM memory and may also include non-volatile storage NVM, such as disk storage.

The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended ISA (EISA) bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, the buses in the figures of the present application are not limited to only one bus or one type of bus.

The present application further provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the processor executes the computer-executable instructions, the noise reduction method in the above method embodiment is implemented.

The present application also provides a computer program product comprising a computer program which, when executed by a processor, implements a noise reduction method as in the above method embodiments.

The computer-readable storage medium may be implemented by any type of volatile or non-volatile memory device or combination thereof, such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk. Readable storage media can be any available media that can be accessed by a general purpose or special purpose computer.

An exemplary readable storage medium is coupled to the processor such the processor can read information from, and write information to, the readable storage medium. Of course, the readable storage medium may also be an integral part of the processor. The processor and the readable storage medium may reside in an Application Specific Integrated Circuits (ASIC). Of course, the processor and the readable storage medium may also reside as discrete components in the apparatus.

The division of the unit is only a logical division, and other division ways are possible in actual implementation, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

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 application 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 functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should 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 or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of noise reduction, the method comprising:

performing narrow-band filtering processing on a first noise signal by using a narrow-band filter to obtain a first narrow-band signal, wherein the first noise signal is obtained by collecting environmental noise at the current moment;

2. The method of claim 1, wherein said filtering the first noise signal with a first filter to obtain a first wideband filtered signal comprises:

and according to the working parameters of the first filter at the current moment, filtering the first noise signal to obtain the first broadband filtering signal.

3. The method of claim 2, wherein determining the operating parameter of the first filter at the current time based on the second signal, the operating parameter of the first filter at the previous time, and the first noise signal comprises:

acquiring a third noise signal after the first noise signal is transmitted through a first transmission channel; the first transmission channel is a transmission channel between a reference microphone for acquiring the first noise signal and the first filter;

and determining the difference value of the product of the working parameter of the first filter at the last moment and a preset value, the parameter adjusting step length, the second signal and the third noise signal as the working parameter of the first filter at the current moment.

4. The method of claim 3, wherein obtaining the third noise signal after passing the first noise signal through the first transmission channel comprises:

and determining a product of a first channel transfer function corresponding to the first transmission channel and the first noise signal as the third noise signal.

5. The method according to any one of claims 1 to 4, wherein said filtering the first narrowband signal with the second filter to obtain a first narrowband filtered signal comprises:

6. The method of claim 5, wherein determining the operating parameters of the second filter at the current time based on the second signal, the operating parameters of the second filter at the previous time, and the first narrowband signal comprises:

obtaining a second narrowband signal after passing the first narrowband signal through a second transmission channel; the second transmission channel is a transmission channel between the narrow band filter and the second filter;

and determining the difference value of the working parameter of the second filter at the last moment and the product of a preset value, the parameter adjusting step length and the second signal and the second narrow-band signal as the working parameter of the second filter at the current moment.

7. The method of claim 1, wherein said denoising the first noise signal according to the first wideband filtered signal and the first narrowband filtered signal comprises:

acquiring a fourth noise signal after the first noise signal is transmitted through a third transmission channel, wherein the third transmission channel is a transmission channel between a reference microphone and a loudspeaker;

superimposing the fourth noise signal with the first wideband filtered signal and the first narrowband filtered signal.

8. A noise reduction chip, comprising: the device comprises a reference microphone, a first filter, a narrow-band filter, a second filter and a first adder, wherein the reference microphone is respectively connected with the first filter, the narrow-band filter and the first adder, the narrow-band filter is also connected with the second filter, and the first filter and the second filter are also respectively connected with the first adder;

the narrow-band filter is used for performing narrow-band filtering processing on the first noise signal to obtain a first narrow-band signal;

the first filter is used for filtering the first noise signal to obtain a first broadband filtering signal;

the second filter is used for filtering the first narrow-band signal to obtain a first narrow-band filtering signal;

the first adder is configured to perform noise reduction processing on the first noise signal according to the first wideband filtered signal and the first narrowband filtered signal.

9. The chip of claim 8, wherein the chip further comprises: a loudspeaker and an error microphone, wherein the loudspeaker is connected with the first adder, and the error microphone is respectively connected with the first filter and the second filter;

the first adder is further configured to perform noise reduction processing on the second noise signal to obtain a second signal;

the loudspeaker is used for playing the second signal;

the error microphone is used for acquiring the second signal.

10. A chip module of making an uproar falls, its characterized in that includes: the noise reduction chip of any one of claims 8 or 9.

11. A noise reduction apparatus, comprising: a noise reduction chip as claimed in any one of claims 8 or 9, or comprising a noise reduction chip module as claimed in claim 10.

12. A noise reduction apparatus, comprising: a processor and a memory; wherein the content of the first and second substances,

the memory is used for storing computer execution instructions;

the processor, configured to execute the computer-executable instructions stored in the memory, to implement the noise reduction method of any one of claims 1 to 7.

13. A computer-readable storage medium having computer-executable instructions stored thereon, which when executed by a processor, implement the noise reduction method of any one of claims 1 to 7.

14. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the noise reduction method of any one of claims 1 to 7.