CN113676815B

CN113676815B - Noise reduction method and device, earphone equipment and storage medium

Info

Publication number: CN113676815B
Application number: CN202111123005.XA
Authority: CN
Inventors: 曲征
Original assignee: Goertek Techology Co Ltd
Current assignee: Goertek Techology Co Ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2022-11-01
Anticipated expiration: 2041-09-24
Also published as: CN113676815A; WO2023045130A1

Abstract

The invention discloses a noise reduction method, a device, earphone equipment and a storage medium, wherein the method is applied to the earphone equipment, the earphone equipment comprises an active noise reduction circuit, a loudspeaker, a sound outlet and a feedback microphone array, the feedback microphone array comprises a plurality of feedback microphones, the distribution plane of the feedback microphone array is vertical to a connecting line between the loudspeaker and the sound outlet, and the center of the feedback microphone array is on the connecting line, the method comprises the following steps: acquiring first noise signals respectively detected by feedback microphones; performing noise reduction processing on each first noise signal through an active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each first noise signal; playing the noise-canceling signal through a speaker. The invention can equivalently realize that the noise at the center of the feedback microphone array is counteracted, and further realize that the noise at the position of the human ear is counteracted.

Description

Noise reduction method and device, earphone equipment and storage medium

Technical Field

The present invention relates to the field of earphone technologies, and in particular, to a noise reduction method and apparatus, an earphone device, and a storage medium.

Background

With the continuous development and maturity of active noise reduction technology, the requirement of a user on the active noise reduction function of the earphone is higher and higher. At present, the principle of the feedback noise reduction earphone is to pick up the noise inside the earmuff by arranging a feedback microphone inside the earmuff, and process the noise through an algorithm to form a reverse sound wave of the noise so as to offset the noise at the feedback noise reduction earphone, thereby achieving the active elimination of the noise. In the technical principle, the feedback microphone is adopted to replace the human ear to pick up the noise, and the noise at the feedback microphone is eliminated, so that the noise at the human ear is also considered to be eliminated. However, when the earphone is worn, the feedback microphone is at a certain distance from the human ear, and when the noise at the feedback microphone is eliminated, the noise at the human ear cannot be completely eliminated, especially for high-frequency noise and slight distance change, the phase will be greatly changed, so that the estimated noise reduction amount has a large difference from the measured value in a high-frequency range.

Disclosure of Invention

The invention mainly aims to provide a noise reduction method, a noise reduction device, earphone equipment and a storage medium, and aims to solve the technical problem that the noise at the ear cannot be completely eliminated by eliminating the noise at a feedback microphone due to the distance between the feedback microphone and the ear.

In order to achieve the above object, the present invention provides a noise reduction method applied to a headphone apparatus, the headphone apparatus including an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, the feedback microphone array including a plurality of feedback microphones, a distribution position of the feedback microphone array conforming to a position condition or conforming to the position condition after error compensation, the position condition being that a distribution plane of the feedback microphone array is perpendicular to a connection line between the speaker and the sound outlet, and a center of the feedback microphone array is on the connection line, the noise reduction method including:

acquiring first noise signals respectively detected by the feedback microphones;

performing noise reduction processing on each first noise signal through the active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each first noise signal;

playing the noise cancellation signal through the speaker.

Optionally, the step of performing noise reduction processing on each of the first noise signals by using the active noise reduction circuit to obtain a noise cancellation signal corresponding to an average signal of each of the first noise signals includes:

averaging the first noise signals to obtain an average signal;

and inputting the average signal into the active noise reduction circuit to carry out noise reduction processing to obtain a noise reduction signal corresponding to the average signal.

Optionally, before the step of acquiring the first noise signal detected by each of the feedback microphones, the method further includes:

acquiring test noise signals respectively detected by the feedback microphones, wherein the test noise signals are signals detected by the feedback microphones after preset test noise is played by the loudspeaker;

averaging all the test noise signals to obtain an average test signal;

calculating an acoustic transfer function from the loudspeaker to the center of the feedback microphone array according to the average test signal;

setting filter coefficients in the active noise reduction circuit according to the acoustic transfer function;

the step of inputting the average signal into the active noise reduction circuit for noise reduction processing to obtain a noise reduction signal corresponding to the average signal includes:

and inputting the average signal into the active noise reduction circuit, and performing noise reduction processing based on the filter coefficient to obtain a noise reduction signal corresponding to the average signal.

Optionally, the active noise reduction circuit includes active noise reduction branches corresponding to the feedback microphones, and the step of performing noise reduction processing on the first noise signals by the active noise reduction circuit to obtain noise reduction signals corresponding to average signals of the first noise signals includes:

inputting each first noise signal into a corresponding active noise reduction branch respectively to perform noise reduction processing, so as to obtain branch noise reduction signals corresponding to each first noise signal respectively;

averaging the branch noise-canceling signals, and taking the result as the noise-canceling signal corresponding to the average signal of the first noise signals.

acquiring test noise signals respectively detected by the feedback microphones, wherein the test noise signals are signals detected by the feedback microphones after preset test noise is played through the loudspeaker;

respectively calculating according to each test noise signal to obtain an acoustic transfer function from the loudspeaker to a corresponding feedback microphone;

respectively setting branch filter coefficients in corresponding active noise reduction branches according to the acoustic transfer functions;

the step of inputting each first noise signal into a corresponding active noise reduction branch for noise reduction processing to obtain branch noise reduction signals corresponding to each first noise signal includes:

and respectively inputting each first noise signal into a corresponding active noise reduction branch, and performing noise reduction processing based on a corresponding branch filter coefficient to obtain branch noise reduction signals respectively corresponding to each first noise signal.

Optionally, when the distribution position of the feedback microphone array meets the position condition after error compensation, the step of averaging the branch noise cancellation signals and taking the result as the noise cancellation signal corresponding to the average signal of each first noise signal includes:

acquiring a weight corresponding to each feedback microphone, wherein the weight is set in advance according to an error of the distribution position of the feedback microphone array relative to the position condition;

and carrying out weighted average on the branch noise-eliminating signals according to corresponding weights, and taking the result as the noise-eliminating signal corresponding to the average signal of the first noise signals.

Optionally, the active noise reduction circuit includes a feedforward active noise reduction circuit and a feedback active noise reduction circuit, the earphone device further includes a feedforward microphone, and the step of performing noise reduction processing on each of the first noise signals by using the active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each of the first noise signals includes:

acquiring a second noise signal detected by the feedforward microphone;

noise reduction processing is carried out on the second noise signal through the feedforward type active noise reduction circuit, and a feedforward noise elimination signal is obtained;

performing noise reduction processing on each first noise signal through the feedback type active noise reduction circuit to obtain a feedback noise reduction signal corresponding to an average signal of each first noise signal;

and adding the feedforward noise-canceling signals and the feedback noise-canceling signals, and taking the result as a noise-canceling signal corresponding to the average signal of the first noise signals.

In order to achieve the above object, the present invention further provides a noise reduction apparatus, where the noise reduction apparatus is disposed in an earphone device, the earphone device includes an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, the feedback microphone array includes a plurality of feedback microphones, a distribution position of the feedback microphone array meets a position condition or meets the position condition after error compensation, the position condition is that a distribution plane of the feedback microphone array is perpendicular to a connection line between the speaker and the sound outlet, and a center of the feedback microphone array is on the connection line, and the noise reduction apparatus includes:

the acquisition module is used for acquiring first noise signals respectively detected by the feedback microphones;

the noise reduction module is used for carrying out noise reduction processing on each first noise signal through the active noise reduction circuit to obtain a noise reduction signal corresponding to the average signal of each first noise signal;

and the playing module is used for playing the noise-eliminating signal through the loudspeaker.

In order to achieve the above object, the present invention further provides an earphone device, which includes an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, where the feedback microphone array includes a plurality of feedback microphones, a distribution position of the feedback microphone array conforms to a position condition or conforms to the position condition after error compensation, the position condition is that a distribution plane of the feedback microphone array is perpendicular to a connection line between the speaker and the sound outlet, and a center of the feedback microphone array is on the connection line, the earphone device further includes a memory, a processor, and a noise reduction program stored in the memory and operable on the processor, and when the noise reduction program is executed by the processor, the noise reduction method as described above is implemented.

Furthermore, to achieve the above object, the present invention also provides a computer readable storage medium, which stores a noise reduction program, and the noise reduction program implements the steps of the noise reduction method as described above when executed by a processor.

In the invention, a feedback microphone array is arranged in the earphone equipment, the feedback microphone array comprises a plurality of feedback microphones, the distribution positions of the feedback microphone array accord with a position condition or accord with the position condition after error compensation, the position condition is that the distribution plane of the feedback microphone array is vertical to a connecting line between a loudspeaker and a sound outlet, and the center of the feedback microphone array is on the connecting line; the active noise reduction circuit in the earphone equipment is used for carrying out noise reduction processing on each first noise signal detected by each feedback microphone to obtain a noise reduction signal corresponding to the average signal of each first noise signal, the noise reduction signal is played through a loudspeaker, noise at the center of the feedback microphone array can be equivalently counteracted, and then noise at the ears of a person can be counteracted.

Drawings

FIG. 1 is a schematic flow chart illustrating a noise reduction method according to a first embodiment of the present invention;

fig. 2 is a schematic diagram illustrating a feedback noise reduction principle according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a noise transmission path of an in-ear headphone according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating a position of a feedback microphone of an in-ear headphone according to an embodiment of the present invention;

fig. 5 is a schematic diagram of functional modules of a noise reduction apparatus according to a preferred embodiment of the present invention.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, fig. 1 is a schematic flow chart of a noise reduction method according to a first embodiment of the present invention.

While a logical order is shown in the flow chart, in some cases, the steps shown or described may be performed in an order different than presented herein. The noise reduction method of the present invention is applied to a headphone device, which may include one or two headphones, and since the noise reduction methods of the two headphones are the same, the following description is made by taking the headphone device including one headphone as a default for convenience of description. In this embodiment, the noise reduction method includes:

step S10, acquiring first noise signals respectively detected by the feedback microphones;

at present, the technical principle of feedback active noise reduction (also called feedback noise reduction) is shown in fig. 2, a feedback microphone (FB mic) is arranged inside an earmuff, noise (also called noise signal) inside the earmuff is picked up by the feedback microphone, and the noise is processed by an algorithm to form reverse sound waves to be offset. d (t) is initial noise inside the earmuff, c (t) is inverse sound wave processed by the algorithm, and e (t) is residual noise after cancellation. Feedback noise reduction is to pick up noise by a feedback microphone instead of the human ear, that is, feedback noise reduction can eliminate noise at the feedback microphone, but it is unknown whether the noise can be eliminated at the human ear. Fig. 3 shows a simplified diagram of an in-ear earphone (taking the in-ear earphone as an example, other types of earphones are also possible), and the rightmost side is a sound outlet of the earphone, which actually penetrates into the ear canal when worn. Assuming that noise enters into the ear from the front sound leakage hole, four paths a, b, c and d are given in fig. 3, a is the path of the noise to the feedback microphone, b is the path of the noise to the human ear, c is the path of the noise to the feedback microphone, d is the path of the speaker to the human ear, according to the feedback noise reduction theory, the noise of the path a and the path c is cancelled out in equal amplitude and opposite phase at the feedback microphone, if it is desired to cancel out the noise in equal amplitude and opposite phase at the human ear, b-a = d-c (where a, b, c and d represent distances) is satisfied, that is, when and only when b-a = d-c, the noise reduction result at the feedback microphone and the noise reduction result at the human ear are consistent. The relative positions of the feedback microphone, the loudspeaker and the human ear are fixed, d-c is a fixed value, but the value of b-a changes with the position of the noise source, so that b-a is not equal to d-c, and the noise at the human ear is not necessarily eliminated. Especially, for the small difference of b-a due to the short wavelength of the high frequency signal, the phase is changed greatly, and finally the difference between the estimated noise reduction amount in the high frequency band and the measured value is large. In order to solve the above problems, the feedback microphone is arranged on the connecting line of the loudspeaker and the sound outlet hole, and b-a = d-c can be basically satisfied, but the feedback microphone is arranged at the position, so that the sound outlet channel of the loudspeaker is blocked, and the sound quality is influenced.

In this respect, in the present embodiment, a noise reduction method is proposed, which aims to make the actions of a plurality of feedback microphones equivalent to the actions of a feedback microphone disposed on a connecting line between a speaker and a sound outlet, that is, to satisfy b-a = d-c, by providing a plurality of feedback microphones in an earphone device, by defining the distribution positions of the plurality of feedback microphones to meet a certain position condition, and by designing a collective calculation method for output signals of the plurality of feedback microphones.

Specifically, the earphone device comprises an active noise reduction circuit, a loudspeaker, a sound outlet and a feedback microphone array, wherein the feedback microphone array comprises a plurality of feedback microphones, the distribution position of the feedback microphone array meets a position condition or meets the position condition after error compensation, the position condition is that the distribution plane of the feedback microphone array is vertical to a connecting line between the loudspeaker and the sound outlet, and the center of the feedback microphone array is on the connecting line.

In the specific embodiment, due to space limitation and other reasons, a feedback microphone array having a distribution position strictly conforming to the position condition may not be provided in the headphone device, that is, a certain error exists between the distribution position of the feedback microphone array and the distribution position of the feedback microphone array conforming to the position condition, where the error compensation means that an output signal (generally, a detected noise signal) of the feedback microphone array is compensated by measuring the error in advance and in a subsequent noise reduction process, so that the compensated output signal of the feedback microphone array is equivalent to an output signal of the feedback microphone array conforming to the position condition (hereinafter, referred to as a standard microphone array). For example, the relative pose between the distribution position of the actual feedback microphone array and the distribution position of the standard microphone array is measured, the actual feedback microphone array is tested through the test signal, a conversion formula for converting the output signal of the actual feedback microphone array into the output signal of the standard microphone array according to the relative pose is calculated according to the test result, and in the subsequent noise reduction process, the output signal of the actual feedback microphone array is converted according to the conversion formula and then participates in noise reduction processing.

In an embodiment, when two feedback microphones are included in the feedback microphone array, as shown in fig. 4, the two feedback microphones may be symmetrically disposed at both sides of the sound outlet hole.

When the earphone device starts an active noise reduction function in the using process, detecting noise signals (hereinafter referred to as first noise signals for distinguishing) through each feedback microphone of the feedback microphone array; since there are a plurality of feedback microphones each detecting a noise signal, respectively, there are a plurality of first noise signals. It should be noted that, when the speaker plays audio, the earphone device may remove the audio signal played by the speaker from the sound signal detected by the feedback microphone, and the remaining portion is used as the first noise signal.

Step S20, carrying out noise reduction processing on each first noise signal through the active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each first noise signal;

for the first noise signals detected by the feedback microphones, the earphone device performs noise reduction processing on the first noise signals through the active noise reduction circuit to obtain noise reduction signals corresponding to average signals of the first noise signals. The average signal is a signal obtained by averaging the first noise signals, and the noise cancellation signal corresponding to the average signal may include a signal generated by the noise reduction processing to cancel the average signal. In this embodiment, the order of the averaging and noise reduction steps is not limited in order to obtain a noise reduction signal corresponding to the average signal; for example, the specific implementation may be that the average of the first noise signals is performed first, and then the average signal is subjected to noise reduction processing to directly obtain the noise cancellation signal corresponding to the average signal, or may be that the noise reduction processing is performed on each of the first noise signals first, and then the results obtained by the noise reduction processing are averaged to indirectly obtain the noise cancellation signal corresponding to the average signal.

The active noise reduction circuit may be a feedback active noise reduction circuit or a hybrid active noise reduction circuit, that is, the active noise reduction circuit includes a feedback active noise reduction circuit and a feedforward active noise reduction circuit, and the circuit design may be designed according to the design manner of the feedback or hybrid active noise reduction circuit, which is not limited in this embodiment. The specific process of performing noise reduction processing on the noise signal by the active noise reduction circuit to obtain the noise reduction signal may also refer to the existing active noise reduction circuit principle, which is not described in detail herein.

In an embodiment, when the active noise reduction circuit is a feedback active noise reduction circuit, the earphone device may perform noise reduction processing on each first noise signal through the feedback active noise reduction circuit to obtain a feedback noise cancellation signal corresponding to an average signal of each first noise signal, where the feedback noise cancellation signal is a final noise cancellation signal.

Further, in an embodiment, when the active noise reduction circuit is a hybrid active noise reduction circuit, that is, when the active noise reduction circuit includes a feedforward active noise reduction circuit and a feedback active noise reduction circuit, the headphone apparatus further includes a feedforward microphone, and the step S20 includes:

step a, acquiring a second noise signal detected by the feedforward microphone;

the feedforward microphone is typically located outside the ear cup for picking up noise prior to the feedback microphone and the human ear. When the active noise reduction function is turned on during use of the headphone apparatus, a noise signal (hereinafter referred to as a second noise signal to distinguish) is detected by the feedforward microphone.

B, performing noise reduction processing on the second noise signal through the feedforward active noise reduction circuit to obtain a feedforward noise reduction signal;

and for a second noise signal detected by the feedforward microphone, the earphone equipment performs noise reduction processing on the second noise signal through the feedforward active noise reduction circuit to obtain a feedforward noise reduction signal, and the feedforward noise reduction signal is used for offsetting the second noise signal. It should be noted that, in this embodiment, the specific process of performing the noise reduction processing by the feedforward active noise reduction circuit is not described in detail herein, and reference may be made to the existing feedforward active noise reduction circuit.

C, performing noise reduction processing on each first noise signal through the feedback type active noise reduction circuit to obtain a feedback noise reduction signal corresponding to the average signal of each first noise signal;

the earphone equipment performs noise reduction processing on each first noise signal through a feedback type active noise reduction circuit to obtain a feedback noise reduction signal corresponding to the average signal of each first noise signal. Specifically, the noise reduction processing may be performed after averaging the first noise signals, or the noise reduction processing may be performed after performing the noise reduction processing on the first noise signals, and then averaging the noise reduction signals. It should be noted that, in this embodiment, the detailed description of the specific process of performing the noise reduction processing by the feedback active noise reduction circuit is omitted, and reference may be made to the existing feedback active noise reduction circuit.

And d, adding the feedforward denoising signal and the feedback denoising signal, and taking the result as a denoising signal corresponding to the average signal of the first noise signals.

After the feedforward noise canceling signal and the feedback noise canceling signal are obtained, the two noise canceling signals are added, and the signal obtained by the addition is used as the noise canceling signal corresponding to the average signal of each first noise signal, namely, the signal obtained by the addition is played through a loudspeaker. It is understood that the feedforward noise canceling signal is used to cancel the first noise signal, the second noise signal picked up at the feedback microphone after cancellation is residual noise, and the feedback noise canceling signal is used to cancel the second noise signal picked up at the feedback microphone, so as to achieve better noise reduction effect through hybrid noise cancellation.

And step S30, playing the noise-eliminating signal through the loudspeaker.

And after the earphone equipment processes the noise-canceling signal, playing the noise-canceling signal through a loudspeaker. Because the distribution plane of the feedback microphone array (or the feedback microphone array after error compensation) is perpendicular to the connecting line between the loudspeaker and the sound outlet, and the center of the feedback microphone array is on the connecting line, the average signal of the first noise signal detected by each feedback microphone in the feedback microphone array can be regarded as the noise signal detected at the center of the feedback microphone array, the noise-canceling signal corresponding to the average signal obtained through noise reduction processing can be regarded as the noise-canceling signal aiming at the noise signal at the center of the feedback microphone array, and then the noise-canceling signal is played, which is equivalent to canceling the noise signal at the center of the feedback microphone array; and because the center of the feedback microphone array is on the connecting line of the loudspeaker and the sound outlet, b-a = d-c can be satisfied, so that when the noise signal is cancelled at the center, the noise signal can also be cancelled at the human ear.

In this embodiment, a feedback microphone array is provided in the earphone device, where the feedback microphone array includes a plurality of feedback microphones, and a distribution position of the feedback microphone array meets a position condition or meets the position condition after error compensation, where the position condition is that a distribution plane of the feedback microphone array is perpendicular to a connection line between the speaker and the sound outlet, and a center of the feedback microphone array is on the connection line; the active noise reduction circuit in the earphone equipment is used for carrying out noise reduction processing on each first noise signal detected by each feedback microphone to obtain a noise reduction signal corresponding to the average signal of each first noise signal, the noise reduction signal is played through a loudspeaker, noise at the center of the feedback microphone array can be equivalently counteracted, and then noise at the ears of a person can be counteracted.

Further, based on the first embodiment described above, a second embodiment of the noise reduction method of the present invention is proposed, and in this embodiment, the step S20 includes:

step S201, averaging each of the first noise signals to obtain an average signal;

step S202, inputting the average signal into the active noise reduction circuit for noise reduction processing, and obtaining a noise reduction signal corresponding to the average signal.

In this embodiment, for the first noise signals detected by the feedback microphones, the headphone apparatus averages the first noise signals to obtain an average signal. The noise signal averaging method can refer to the existing signal averaging method, and is not described in detail herein. And after the average signal is obtained, inputting the average signal into an active noise reduction circuit for noise reduction processing.

When the active noise reduction circuit is a feedback active noise reduction circuit, the earphone device inputs an average signal obtained by averaging all the first noise signals into the feedback active noise reduction circuit to perform noise reduction processing, so as to obtain a feedback noise cancellation signal corresponding to the average signal, and the feedback noise cancellation signal is played through a loudspeaker as a final noise cancellation signal. The filter coefficient of the feedback filter in the feedback active noise reduction circuit can be designed by testing in advance, and the design mode can refer to the existing design method of the feedback filter, wherein when the output signal (detected noise signal) of the feedback microphone is needed, the output signal of each feedback microphone can be averaged and then participate in the filter design.

When the active noise reduction circuit is a hybrid active noise reduction circuit, namely the active noise reduction circuit comprises a feedforward active noise reduction circuit and a feedback active noise reduction circuit, the earphone equipment detects a second noise signal through a feedforward microphone, and inputs the second noise signal into the feedforward active noise reduction circuit for noise reduction processing to obtain a feedforward noise reduction signal; average signals obtained by averaging first noise signals detected by all feedback microphones are input into a feedback type active noise reduction circuit for noise reduction processing, and feedback noise reduction signals corresponding to the average signals are obtained; and adding the feedforward noise-canceling signals and the feedback noise-canceling signals to obtain a result, and using the result as the noise-canceling signal corresponding to the average signal of each first noise signal, namely playing the result obtained by adding through a loudspeaker. Similarly, the filter coefficients of the feedforward filter in the feedforward active noise reduction circuit and the feedback filter in the feedback active noise reduction circuit may be designed by testing in advance, and the design method may refer to the existing design method of the feedforward filter and the feedback filter, wherein when the output signal (detected noise signal) of the feedback microphone is needed, the output signal of each feedback microphone may be averaged and then participate in the filter design.

Further, in an embodiment, before the step S10, the method further includes:

step A10, obtaining test noise signals respectively detected by each feedback microphone, wherein the test noise signals are signals detected by each feedback microphone after preset test noise is played by the loudspeaker;

the filter coefficients in the active noise reduction circuit may be set by playing the test noise and calculating the acoustic transfer function. Specifically, a piece of noise for test (hereinafter, referred to as test noise) may be set in advance in the headphone apparatus, the test noise may be played through a speaker in the headphone apparatus, and a noise signal may be detected through each feedback microphone, and the noise signal may be referred to as a test noise signal.

Step A20, averaging all the test noise signals to obtain an average test signal;

step A30, calculating an acoustic transfer function from the loudspeaker to the center of the feedback microphone array according to the average test signal;

averaging the test noise signals results in an average test signal that can be considered as the noise signal picked up by a microphone placed in the center of the feedback microphone array (where in practice no microphone is placed). From this average test signal, an acoustic transfer function of the loudspeaker to the center of the feedback microphone array can be calculated, which reflects the transfer relationship between the noise signal played by the loudspeaker and the noise signal picked up by the microphone at the center of the feedback microphone array. The method for calculating the acoustic transfer function according to the average test signal may refer to an existing acoustic transfer function calculation method, which is not described herein again.

Step A40, setting a filter coefficient in the active noise reduction circuit according to the acoustic transfer function;

after the acoustic transfer function from the loudspeaker to the center of the feedback microphone array is obtained through calculation, the filter coefficient in the active noise reduction circuit can be set according to the acoustic transfer function. Specifically, the method for setting the filter coefficient according to the acoustic transfer function is commonly referred to the existing filter coefficient setting method, which is not described herein again.

If the active noise reduction circuit is a feedback active noise reduction circuit, the filter coefficient of the feedback filter in the feedback active noise reduction circuit is set according to the acoustic transfer function from the speaker to the center of the feedback microphone array. If the active noise reduction circuit is a hybrid active noise reduction circuit, further, a section of test noise (hereinafter referred to as external test noise) may be preset in an external test device, the external test noise is played through the external test device, the external test noise signal is detected through a feedforward microphone and a feedback microphone, and an acoustic transfer function (hereinafter referred to as a first function) from an external sound source to the feedforward microphone is calculated according to the external test noise signal detected by the feedforward microphone; averaging the external test noise signals detected by the feedback microphones to obtain an average external test signal, and calculating an acoustic transfer function (hereinafter referred to as a second function) from the feedforward microphone to the center of the feedback microphone array according to the external test noise signals detected by the feedforward microphone and the average test signal; and jointly setting the filter coefficient of a feedforward filter in the feedforward active noise reduction circuit and the filter coefficient of a feedback filter in the feedback active noise reduction circuit according to the first function, the second function and the third function (the acoustic transfer function from the loudspeaker to the center of the feedback microphone array).

The step S202 includes:

step S2021, inputting the average signal into the active noise reduction circuit, and performing noise reduction processing based on the filter coefficient to obtain a noise reduction signal corresponding to the average signal.

After the filter coefficient in the active noise reduction circuit is set, when the active noise reduction function is started in the use process, after the average signal of each first noise signal is obtained through calculation, the average signal can be input into the active noise reduction circuit, and noise reduction processing is performed based on the set filter coefficient in the active noise reduction circuit, so that a noise reduction signal corresponding to the average signal is obtained. It should be noted that, in the active noise reduction circuit, the specific process of performing noise reduction processing on a signal based on a filter to obtain a noise reduction signal may refer to an existing active noise reduction circuit, which is not described herein again.

Further, based on the first embodiment described above, a third embodiment of the noise reduction method of the present invention is proposed, and in this embodiment, the step S20 includes:

step S203, inputting each first noise signal into a corresponding active noise reduction branch respectively for noise reduction processing, so as to obtain branch noise reduction signals corresponding to each first noise signal respectively;

step S204, averaging the branch noise cancellation signals, and using the result as the noise cancellation signal corresponding to the average signal of the first noise signals.

In this embodiment, for the first noise signal detected by each feedback microphone, noise reduction processing may be performed first, and then the noise-reduced signal may be averaged.

Specifically, the active noise reduction circuit may include active noise reduction branches corresponding to the feedback microphones, that is, one feedback microphone corresponds to one active noise reduction branch. For the first noise signals detected by each feedback microphone, the earphone device may first input each first noise signal into the corresponding active noise reduction branch for noise reduction processing, so as to obtain branch noise reduction signals corresponding to each first noise signal. That is, a first noise signal detected by one feedback microphone is input into an active noise reduction branch corresponding to the feedback microphone for noise reduction processing, so as to obtain a branch noise reduction signal corresponding to the first noise signal.

Averaging the noise-canceling signals of the branches, and taking the averaged signal as the noise-canceling signal corresponding to the average signal of each first noise signal, that is, although the noise-canceling signal is not obtained by directly performing noise-reducing processing on the average signal of each first noise signal, the signal obtained by averaging the average signal of each first noise signal after performing noise-reducing processing on the average signal of each first noise signal by using the corresponding active noise-reducing branch can be regarded as the noise-canceling signal corresponding to the average signal of each first noise signal.

The active noise reduction branch circuit can be a feedback type active noise reduction circuit or a hybrid type active noise reduction circuit.

When the active noise reduction branch is a feedback active noise reduction circuit, the earphone device inputs each first noise signal into the corresponding feedback active noise reduction circuit to perform noise reduction processing, so as to obtain feedback noise cancellation signals (i.e. branch noise cancellation signals) corresponding to each first noise signal, and directly uses the signal obtained by averaging each branch noise cancellation signal as the noise cancellation signal corresponding to the average signal of each first noise signal, and plays the noise cancellation signal through a loudspeaker. The filter coefficients of the feedback filters in the feedback active noise reduction circuits can be designed by testing in advance, and the design method can refer to the existing design method of the feedback filters, wherein when the output signals (detected noise signals) of the feedback microphones are needed, the output signals of the corresponding feedback microphones are used to participate in the design of the corresponding filters.

When the active noise reduction branch circuits are hybrid active noise reduction circuits, different feedback active noise reduction circuits can be adopted by each active noise reduction branch circuit, but one feedforward active noise reduction circuit is shared; the earphone equipment detects a second noise signal through a feedforward microphone, inputs the second noise signal into a feedforward active noise reduction circuit for noise reduction processing, and obtains a feedforward noise reduction signal; respectively inputting the first noise signals detected by each feedback microphone into corresponding feedback type active noise reduction circuits for noise reduction processing to obtain each feedback noise reduction signal; and respectively adding the feedforward denoising signals and the feedback denoising signals and then averaging the feedforward denoising signals or averaging the feedback denoising signals and then adding the feedback denoising signals and the feedforward denoising signals, and taking the calculated result as the denoising signal corresponding to the average signal of each first noise signal, namely playing the calculated result through a loudspeaker. Similarly, the filter coefficients of the feedforward filter in the feedforward active noise reduction circuit and the feedback filter in the feedback active noise reduction circuit may be designed by testing in advance, and the design method may refer to the existing design method of the feedforward filter and the feedback filter, wherein when the output signal (detected noise signal) of the feedback microphone needs to be used, the output signal of the corresponding feedback microphone is used to participate in the design of the corresponding filter.

Further, in an embodiment, before the step S10, the method further includes:

step B10, obtaining test noise signals respectively detected by the feedback microphones, wherein the test noise signals are signals detected by the feedback microphones after preset test noise is played through the loudspeaker;

the filter coefficients in the active noise reduction circuit may be set by playing the test noise and calculating the acoustic transfer function. Specifically, a piece of noise for test (hereinafter referred to as test noise) may be set in advance in the headphone apparatus, the test noise may be played through a speaker in the headphone apparatus, and a noise signal may be detected through each feedback microphone, and the noise signal may be referred to as a test noise signal.

Step B20, calculating to obtain an acoustic transfer function from the loudspeaker to the corresponding feedback microphone according to each test noise signal;

step B30, branch filter coefficients in corresponding active noise reduction branches are set according to the acoustic transfer functions respectively;

and respectively calculating the acoustic transfer function from the loudspeaker to the corresponding feedback microphone according to the test noise signals. That is, for each feedback microphone, the test noise signal detected by the feedback microphone is used to calculate the acoustic transfer function of the speaker to the feedback microphone. Then one feedback microphone corresponds to one acoustic transfer function. And respectively setting branch filter coefficients in the corresponding active noise reduction branches according to the acoustic transfer functions, namely, for each feedback microphone, setting the branch filter coefficients in the active noise reduction branches corresponding to the feedback microphone by adopting the acoustic transfer function corresponding to the feedback microphone.

It should be noted that, if the active noise reduction branch is a feedback active noise reduction circuit, the filter coefficient of the feedback filter in each feedback active noise reduction circuit is set according to the acoustic transfer function from the speaker to each feedback microphone. If the active noise reduction circuit is a hybrid active noise reduction circuit, further, a section of test noise (hereinafter referred to as external test noise) may be preset in an external test device, the external test noise is played through the external test device, the external test noise signal is detected through a feedforward microphone and a feedback microphone, and an acoustic transfer function (hereinafter referred to as a first function) from an external sound source to the feedforward microphone is calculated according to the external test noise signal detected by the feedforward microphone; respectively calculating acoustic transfer functions (hereinafter referred to as second functions) from the feedforward microphones to the feedback microphones according to the external test noise signals detected by the feedforward microphones and the external test noise signals detected by the feedback microphones; and jointly setting the filter coefficient of the feedforward filter in the feedforward active noise reduction circuit and the filter coefficient of the feedback filter in each feedback active noise reduction circuit according to the first function, each second function and each third function (the acoustic transfer function from the loudspeaker to the feedback microphone).

The step S204 includes:

step S2041, inputting each of the first noise signals into a corresponding active noise reduction branch, and performing noise reduction processing based on a corresponding branch filter coefficient to obtain a branch noise reduction signal corresponding to each of the first noise signals.

After the filter coefficients of the branches in the active noise reduction branches are set, when the active noise reduction function is started in the use process, the earphone device can input each first noise signal into the corresponding active noise reduction branch respectively, and perform noise reduction processing based on the filter coefficients set in the active noise reduction branches to obtain branch noise reduction signals corresponding to each first noise signal respectively. It should be noted that, in the active noise reduction branch, a specific process of performing noise reduction processing on a signal based on a filter to obtain a noise reduction signal may refer to an existing active noise reduction circuit, which is not described herein again.

Further, in an embodiment, when the distributed position of the feedback microphone array meets the position condition after being error-compensated, the step S20 includes:

step S205, acquiring a weight corresponding to each feedback microphone, wherein the weight is set in advance according to an error of the distribution position of the feedback microphone array relative to the position condition;

when there is an error between the distribution position of the feedback microphone array and the position condition, the error may be compensated, and in the present embodiment, the error may be compensated in such a manner that the weight corresponding to each feedback microphone array is set in advance according to the error of the distribution position of the feedback microphone array with respect to the position condition. Specifically, the weights may be set by a test method so that a noise signal obtained by weighted averaging of noise signals detected by the respective feedback microphones with the set weights coincides with a noise signal at the center position of the feedback microphone array.

Step S206, performing weighted average on each branch denoising signal according to the corresponding weight, and taking the result as a denoising signal corresponding to the average signal of each first noise signal.

After the first noise signal is detected by each feedback microphone, the branch noise cancellation signals may be weighted-averaged according to the corresponding weight. The feedback microphone, the first noise signal, the active noise reduction branch, the weight, and the branch noise cancellation signal are in one-to-one correspondence, and the weighted average is obtained by multiplying each branch noise cancellation signal by the corresponding weight and then averaging. And taking the weighted average result as a noise elimination signal corresponding to the average signal of the first noise signals.

Further, in an embodiment, when averaging and then performing the noise reduction processing on each first noise signal, the first noise signals may be weighted and averaged according to the corresponding weight to obtain an average signal, and then the average signal is input to the active noise reduction circuit to perform the noise reduction processing to obtain a noise reduction signal corresponding to the average signal of each first noise signal.

In addition, an embodiment of the present invention further provides a noise reduction apparatus, where the noise reduction apparatus is disposed in an earphone device, the earphone device includes an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, the feedback microphone array includes a plurality of feedback microphones, a distribution position of the feedback microphone array conforms to a position condition or conforms to the position condition after error compensation, the position condition is that a distribution plane of the feedback microphone array is perpendicular to a connection line between the speaker and the sound outlet, and a center of the feedback microphone array is on the connection line, with reference to fig. 5, the noise reduction apparatus includes:

an obtaining module 10, configured to obtain first noise signals detected by the feedback microphones respectively;

a noise reduction module 20, configured to perform noise reduction processing on each first noise signal through the active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each first noise signal;

and a playing module 30, configured to play the noise-canceling signal through the speaker.

Further, the noise reduction module 20 includes:

a first averaging unit, configured to average each of the first noise signals to obtain an average signal;

and the first noise reduction unit is used for inputting the average signal into the active noise reduction circuit to carry out noise reduction processing so as to obtain a noise reduction signal corresponding to the average signal.

Further, the obtaining module 10 is further configured to obtain a test noise signal detected by each feedback microphone, where the test noise signal is a signal detected by each feedback microphone after a preset test noise is played by the speaker;

the device further comprises:

the averaging module is used for averaging all the test noise signals to obtain an average test signal;

the first calculation module is used for calculating an acoustic transfer function from the loudspeaker to the center of the feedback microphone array according to the average test signal;

the first setting module is used for setting the filter coefficient in the active noise reduction circuit according to the acoustic transfer function;

the first denoising unit is further configured to:

Further, the active noise reduction circuit includes active noise reduction branches corresponding to the feedback microphones respectively, and the noise reduction module 20 includes:

the second noise reduction unit is used for inputting each first noise signal into a corresponding active noise reduction branch respectively to carry out noise reduction processing so as to obtain branch noise reduction signals corresponding to each first noise signal;

and the second averaging unit is used for averaging the branch noise-canceling signals, and taking the result as the noise-canceling signal corresponding to the average signal of the first noise signals.

the device further comprises:

the second calculation module is used for calculating and obtaining an acoustic transfer function from the loudspeaker to the corresponding feedback microphone according to each test noise signal;

the second setting module is used for setting branch filter coefficients in corresponding active noise reduction branches according to the acoustic transfer functions respectively;

the second averaging unit is further configured to:

Further, when the distribution position of the feedback microphone array meets the position condition after error compensation, the second averaging unit is further configured to:

Further, the active noise reduction circuit includes a feedforward active noise reduction circuit and a feedback active noise reduction circuit, the headphone apparatus further includes a feedforward microphone, and the noise reduction module 20 includes:

an acquisition unit configured to acquire a second noise signal detected by the feedforward microphone;

the third noise reduction unit is used for carrying out noise reduction processing on the second noise signal through the feedforward active noise reduction circuit to obtain a feedforward noise reduction signal;

the fourth noise reduction unit is used for performing noise reduction processing on each first noise signal through the feedback type active noise reduction circuit to obtain a feedback noise reduction signal corresponding to the average signal of each first noise signal;

and a calculating unit, configured to add the feedforward noise canceling signal and the feedback noise canceling signal, and use the result as a noise canceling signal corresponding to an average signal of the first noise signals.

The specific implementation of the noise reduction apparatus of the present invention has basically the same extension as that of each embodiment of the noise reduction method, and is not described herein again.

The earphone device of the present invention may include an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, where the feedback microphone array includes a plurality of feedback microphones, a distribution position of the feedback microphone array conforms to a position condition or conforms to the position condition after error compensation, the position condition is that a distribution plane of the feedback microphone array is perpendicular to a connection line between the speaker and the sound outlet, and a center of the feedback microphone array is on the connection line, the earphone device further includes a memory, a processor, and a noise reduction program stored in the memory and executable on the processor, and the noise reduction program when executed by the processor performs operations of:

playing the noise cancellation signal through the speaker.

Further, the performing, by the active noise reduction circuit, noise reduction processing on each of the first noise signals to obtain a noise cancellation signal corresponding to an average signal of each of the first noise signals includes:

averaging the first noise signals to obtain an average signal;

and inputting the average signal into the active noise reduction circuit to carry out noise reduction processing, so as to obtain a noise reduction signal corresponding to the average signal.

Further, before the obtaining the first noise signal detected by each of the feedback microphones, the method further includes:

averaging the test noise signals to obtain an average test signal;

the inputting the average signal into the active noise reduction circuit for noise reduction processing to obtain a noise reduction signal corresponding to the average signal includes:

Further, the active noise reduction circuit includes active noise reduction branches corresponding to the feedback microphones, and the performing noise reduction processing on the first noise signals by the active noise reduction circuit to obtain noise reduction signals corresponding to average signals of the first noise signals includes:

averaging the branch noise-canceling signals, and taking the result as a noise-canceling signal corresponding to the average signal of the first noise signals.

Further, when the distribution position of the feedback microphone array meets the position condition after error compensation, the averaging the branch noise cancellation signals, and taking the result as the noise cancellation signal corresponding to the average signal of each first noise signal includes:

acquiring a weight corresponding to each feedback microphone, wherein the weight is set in advance according to the error of the distribution position of the feedback microphone array relative to the position condition;

Further, the active noise reduction circuit includes a feedforward active noise reduction circuit and a feedback active noise reduction circuit, the earphone device further includes a feedforward microphone, and performing noise reduction processing on each of the first noise signals by the active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each of the first noise signals includes:

acquiring a second noise signal detected by the feedforward microphone;

Furthermore, an embodiment of the present invention further provides a computer-readable storage medium, where a noise reduction program is stored on the storage medium, and the noise reduction program, when executed by a processor, implements the steps of the noise reduction method as described above.

The embodiments of the headphone device and the computer-readable storage medium of the present invention can refer to the embodiments of the noise reduction method of the present invention, and are not described herein again.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention or portions thereof contributing to the prior art may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A noise reduction method applied to a headphone device including an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, wherein the feedback microphone array includes a plurality of feedback microphones, and a distribution position of the feedback microphone array meets a position condition or meets the position condition after error compensation, the position condition is that a distribution plane of the feedback microphone array is perpendicular to a line between the speaker and the sound outlet, and a center of the feedback microphone array is on the line, the noise reduction method comprising:

playing the noise-canceling signal through the speaker;

the active noise reduction circuit comprises active noise reduction branches corresponding to the feedback microphones respectively, and the step of performing noise reduction processing on the first noise signals through the active noise reduction circuit to obtain noise reduction signals corresponding to average signals of the first noise signals comprises the following steps:

averaging the branch noise-eliminating signals, and taking the result as a noise-eliminating signal corresponding to the average signal of the first noise signals;

before the step of obtaining the first noise signal detected by each feedback microphone, the method further includes:

respectively calculating according to each test noise signal to obtain an acoustic transfer function from the loudspeaker to the corresponding feedback microphone;

2. The noise reduction method according to claim 1, wherein the step of performing noise reduction processing on each of the first noise signals by the active noise reduction circuit to obtain a noise cancellation signal corresponding to an average signal of each of the first noise signals comprises:

averaging the first noise signals to obtain an average signal;

3. The noise reduction method according to claim 2, wherein the step of obtaining the first noise signal detected by each of the feedback microphones is preceded by:

averaging all the test noise signals to obtain an average test signal;

4. The noise reduction method according to claim 1, wherein when the distribution position of the feedback microphone array meets the position condition after error compensation, the step of averaging the branch noise cancellation signals and taking the result as the noise cancellation signal corresponding to the average signal of each first noise signal comprises:

5. The noise reduction method according to any one of claims 1 to 4, wherein the active noise reduction circuit includes a feedforward active noise reduction circuit and a feedback active noise reduction circuit, the headphone apparatus further includes a feedforward microphone, and the step of performing noise reduction processing on each of the first noise signals by the active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each of the first noise signals includes:

acquiring a second noise signal detected by the feedforward microphone;

6. A noise reduction apparatus disposed in an earphone device, the earphone device including an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, the feedback microphone array including a plurality of feedback microphones, a distribution position of the feedback microphone array conforming to a position condition or conforming to the position condition after error compensation, the position condition being that a distribution plane of the feedback microphone array is perpendicular to a line between the speaker and the sound outlet, and a center of the feedback microphone array is on the line, the noise reduction apparatus comprising:

the noise reduction module is used for carrying out noise reduction processing on each first noise signal through the active noise reduction circuit to obtain a noise reduction signal corresponding to an average signal of each first noise signal;

the playing module is used for playing the noise-eliminating signal through the loudspeaker;

the active noise reduction circuit comprises active noise reduction branches corresponding to the feedback microphones respectively, and the noise reduction module comprises:

the second noise reduction unit is used for inputting each first noise signal into a corresponding active noise reduction branch respectively to carry out noise reduction processing so as to obtain branch noise reduction signals corresponding to each first noise signal respectively;

a second averaging unit, configured to average the branch noise cancellation signals, and use the result as a noise cancellation signal corresponding to an average signal of the first noise signals;

the acquiring module is further configured to acquire a test noise signal detected by each of the feedback microphones, where the test noise signal is a signal detected by each of the feedback microphones after a preset test noise is played by the speaker;

the device further comprises:

the second averaging unit is further configured to:

7. An earphone device, comprising an active noise reduction circuit, a speaker, a sound outlet, and a feedback microphone array, wherein the feedback microphone array comprises a plurality of feedback microphones, and the distribution position of the feedback microphone array conforms to a position condition or conforms to the position condition after error compensation, the position condition is that the distribution plane of the feedback microphone array is perpendicular to the connection line between the speaker and the sound outlet, and the center of the feedback microphone array is on the connection line, the earphone device further comprises a memory, a processor, and a noise reduction program stored in the memory and operable on the processor, and the noise reduction program when executed by the processor implements the steps of the noise reduction method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that a noise reduction program is stored on the computer-readable storage medium, which when executed by a processor implements the steps of the noise reduction method according to any one of claims 1 to 5.