CN114786085A - Noise reduction control method and device, noise reduction earphone and storage medium - Google Patents

Abstract

The present disclosure relates to a noise reduction control method, a device, a noise reduction earphone and a storage medium. The noise reduction control method includes: acquiring an environmental time domain signal, and acquiring an ear canal time domain signal. domain signal and the preset frequency response function to determine the target noise reduction amount; according to the preset noise reduction configuration information and the target noise reduction amount, the sound leakage compensation gear corresponding to the target noise reduction amount is determined as the target sound leakage compensation gear determine the target filter parameters based on the target sound leakage compensation gear; adjust the filter parameters in the preset noise reduction filter to the target filter parameters. By using the method in the present disclosure, when the earphone is loosely worn, the filter parameters in the preset noise reduction filter can be adjusted in time to perform sound leakage compensation, so as to ensure a good noise reduction effect and improve user experience.

Description

Noise reduction control method, device, noise reduction earphone and storage medium

technical field

The present disclosure relates to the field of signal processing, and in particular, to a noise reduction control method, a device, a noise reduction earphone and a storage medium.

Background technique

Active Noise Cancellation (ANC), also known as Active Noise Control (ANC), is a method that actively generates a signal with the same energy and opposite phase as the noise source, so that the acoustic signal interferes with the noise source signal. The technology of sound wave cancellation. Active noise reduction technology is widely used in multimedia fields with audio playback functions such as headphones, ship cabins, car cockpits, car speaker systems, and smart homes.

At present, after a user wears the earphone for a long time, a gap is formed between the earphone and the ear canal, and the fit between the earphone and the ear is reduced, so that the noise reduction effect is poor.

SUMMARY OF THE INVENTION

In order to overcome the problems existing in the related art, the present disclosure provides a noise reduction control method, a device, a noise reduction earphone and a storage medium.

According to a first aspect of the embodiments of the present disclosure, a noise reduction control method is provided, applied to an earphone, and the method includes:

acquiring an environmental time domain signal, wherein the environmental time domain signal refers to a sound wave signal in the environment around the earphone represented by a time domain representation;

acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to an acoustic wave signal in the ear canal represented by a time domain representation;

If the environmental time-domain signal and the ear canal time-domain signal satisfy the preset filter parameter adjustment conditions, then based on the environmental time-domain signal and the ear canal time-domain signal and the preset frequency response function, determine target noise reduction amount;

According to the preset noise reduction configuration information and the target noise reduction amount, the sound leakage compensation gear corresponding to the target noise reduction amount is determined as the target sound leakage compensation gear, wherein the noise reduction configuration information is used for Characterizing the correspondence between the noise reduction threshold and the sound leakage compensation gear, the noise reduction configuration information includes a plurality of noise reduction thresholds and a sound leakage compensation gear corresponding to each of the noise reduction thresholds;

determining target filter parameters based on the target acoustic leakage compensation gear;

The filter parameters in the preset noise reduction filter are adjusted to the target filter parameters, wherein the noise reduction filter is used to perform noise reduction filtering processing on the input sound wave signal.

In an exemplary embodiment, the method further includes: using the following method to determine whether the ambient time domain signal and the ear canal time domain signal satisfy preset filter parameter adjustment conditions:

Determine the total energy of the environmental time domain signal based on the environmental time domain signal, wherein the environmental time domain signal includes a plurality of frequency points, and the total energy of the environmental time domain signal refers to each frequency in the environmental time domain signal the sum of the energies of the points;

Based on the ear canal time domain signal, the total energy of the ear canal time domain signal is determined, wherein the ear canal time domain signal includes a plurality of frequency points, and the total energy of the ear canal time domain signal refers to the time of the ear canal The sum of the energy of each frequency point in the domain signal;

If the ratio of the total energy of the environmental time domain signal to the total energy of the ear canal time domain signal is greater than or equal to a preset energy threshold, it is determined that the preset filter parameter adjustment conditions are met.

In an exemplary embodiment, the determining the target noise reduction amount based on the environmental time domain signal and the ear canal time domain signal and a preset frequency response function includes:

Fourier transform is performed on the environmental time domain signal and the ear canal time domain signal respectively to obtain the environmental frequency domain signal and the ear canal frequency domain signal, wherein the environmental frequency domain signal refers to the frequency domain representation The represented sound wave signal in the surrounding environment of the earphone, the ear canal frequency domain signal refers to the sound wave signal in the ear canal represented by the frequency domain representation;

obtaining a cross frequency response based on the ambient frequency domain signal and the ear canal frequency domain signal and a preset frequency response function, where the cross frequency response is related to a frequency point;

obtaining a reference noise reduction amount according to the cross frequency response;

According to the reference noise reduction amount, the average noise reduction amount of the target frequency band is obtained, and the average noise reduction amount is determined as the target noise reduction amount, wherein the average noise reduction amount refers to the average noise reduction amount in the target frequency band. The average value of the energy of each frequency point.

In an exemplary embodiment, the sound leakage compensation gear corresponding to the target noise reduction amount is determined as the target sound leakage compensation gear according to the preset noise reduction configuration information and the target noise reduction amount ,include:

Obtain a preset noise reduction threshold set, where the preset noise reduction threshold set includes a plurality of noise parameter values arranged from small to large, and a plurality of the noise parameter values constitute a plurality of noise reduction amount thresholds, and the noise reduction amount The threshold value corresponds to the sound leakage compensation gear;

determining the noise reduction threshold to which the target noise reduction belongs according to the target noise reduction and the preset noise reduction threshold set;

According to the noise reduction amount threshold to which the target noise reduction amount belongs, the sound leakage compensation gear position corresponding to the noise reduction amount threshold to which the target noise reduction amount belongs is determined as the target sound leakage compensation gear position.

In an exemplary embodiment, the target filter parameter is determined based on the target sound leakage compensation gear, and the filter parameter in the preset noise reduction filter is adjusted to the target filter parameter, including: :

acquiring chip configuration information, where the chip configuration information is used to represent whether the filter coefficients stored in the chip support updating;

If the filter coefficients stored in the chip support updating, determine the target filter coefficients based on the target sound leakage compensation gear, and adjust the filter coefficients in the preset noise reduction filter to the target filter coefficients ;

If the filter system stored in the chip does not support updating, determine the target filter gain based on the target sound leakage compensation gear, and adjust the filter gain in the preset noise reduction filter to the target filter gain.

In an exemplary embodiment, the filter parameters in the preset noise reduction filter include:

the filter parameters in the feedforward filter; or,

Filter parameters in feedforward filters and filter parameters in feedback filters.

According to a second aspect of the embodiments of the present disclosure, there is provided a noise reduction control device applied to an earphone, the noise reduction control device comprising:

a first acquisition module, configured to acquire an environmental time-domain signal, wherein the environmental time-domain signal refers to a sound wave signal in the surrounding environment of the earphone represented by a time-domain representation;

The second acquisition module is configured to acquire the ear canal time domain signal, wherein the ear canal time domain signal refers to the acoustic wave signal in the ear canal represented by the time domain representation;

a first determining module, configured to, if the environmental time domain signal and the ear canal time domain signal satisfy a preset filter parameter adjustment condition, then, based on the environmental time domain signal and the ear canal time domain signal and The preset frequency response function determines the target noise reduction amount;

The second determination module is configured to, according to the preset noise reduction configuration information and the target noise reduction amount, determine the sound leakage compensation gear corresponding to the target noise reduction amount as the target sound leakage compensation gear, wherein, The noise reduction configuration information is used to represent the corresponding relationship between the noise reduction amount threshold and the sound leakage compensation gear, and the noise reduction configuration information includes a plurality of noise reduction amount thresholds and a corresponding noise reduction amount threshold. Acoustic leakage compensation gear;

a third determining module configured to determine target filter parameters based on the target acoustic leakage compensation gear;

The adjustment module is configured to adjust the filter parameters in the preset noise reduction filter to the target filter parameters, wherein the noise reduction filter is used to perform noise reduction filtering processing on the input sound wave signal.

In an exemplary embodiment, the first determining module is further configured to:

Determine the total energy of the environmental time domain signal based on the environmental time domain signal, wherein the environmental time domain signal includes a plurality of frequency points, and the total energy of the environmental time domain signal refers to each frequency in the environmental time domain signal the sum of the energies of the points;

Based on the ear canal time domain signal, the total energy of the ear canal time domain signal is determined, wherein the ear canal time domain signal includes a plurality of frequency points, and the total energy of the ear canal time domain signal refers to the time of the ear canal The sum of the energy of each frequency point in the domain signal;

If the ratio of the total energy of the environmental time domain signal to the total energy of the ear canal time domain signal is greater than or equal to a preset energy threshold, it is determined that the preset filter parameter adjustment conditions are met.

In an exemplary embodiment, the first determining module is further configured to:

Fourier transform is performed on the environmental time domain signal and the ear canal time domain signal respectively to obtain the environmental frequency domain signal and the ear canal frequency domain signal, wherein the environmental frequency domain signal refers to the frequency domain representation The represented sound wave signal in the surrounding environment of the earphone, the ear canal frequency domain signal refers to the sound wave signal in the ear canal represented by the frequency domain representation;

obtaining a cross frequency response based on the ambient frequency domain signal and the ear canal frequency domain signal and a preset frequency response function, where the cross frequency response is related to a frequency point;

obtaining a reference noise reduction amount according to the cross frequency response;

According to the reference noise reduction amount, the average noise reduction amount of the target frequency band is obtained, and the average noise reduction amount is determined as the target noise reduction amount, wherein the average noise reduction amount refers to the average noise reduction amount in the target frequency band. The average value of the energy of each frequency point.

In an exemplary embodiment, the second determining module is further configured to:

Obtain a preset noise reduction threshold set, where the preset noise reduction threshold set includes a plurality of noise parameter values arranged from small to large, and a plurality of the noise parameter values constitute a plurality of noise reduction amount thresholds, and the noise reduction amount The threshold value corresponds to the sound leakage compensation gear;

determining the noise reduction threshold to which the target noise reduction belongs according to the target noise reduction and the preset noise reduction threshold set;

According to the noise reduction amount threshold to which the target noise reduction amount belongs, the sound leakage compensation gear position corresponding to the noise reduction amount threshold to which the target noise reduction amount belongs is determined as the target sound leakage compensation gear position.

In an exemplary embodiment, the third determining module for the noise reduction amount threshold is further configured to:

acquiring chip configuration information, where the chip configuration information is used to represent whether the filter coefficients stored in the chip support updating;

If the filter coefficients stored in the chip support updating, determine the target filter coefficients based on the target sound leakage compensation gear, and adjust the filter coefficients in the preset noise reduction filter to the target filter coefficients ;

If the filter system stored in the chip does not support updating, determine the target filter gain based on the target sound leakage compensation gear, and adjust the filter gain in the preset noise reduction filter to the target filter gain.

In an exemplary embodiment, the filter parameters in the preset noise reduction filter include:

the filter parameters in the feedforward filter; or,

Filter parameters in feedforward filters and filter parameters in feedback filters.

According to a third aspect of the embodiments of the present disclosure, a noise reduction earphone is provided, the earphone includes a housing and a feedforward microphone, a feedback microphone, a speaker, and a controller disposed on the housing:

The feedforward microphone is used to collect the sound wave signal in the surrounding environment of the earphone;

The feedback microphone is used to collect the sound wave signal in the ear canal;

The loudspeaker is used for playing sound wave signal;

the controller is respectively connected in communication with the feedforward microphone, the feedback microphone and the speaker, the controller includes a processor and a memory, the memory stores computer program instructions executable by the processor, The processor is configured to invoke the computer program instructions to perform the method of any one of the first aspects of the embodiments of the present disclosure.

According to a fourth aspect of the embodiments of the present disclosure, there is provided a non-transitory computer-readable storage medium on which computer program instructions are stored, characterized in that, when the computer program instructions are invoked by a processor, the execution is performed as implemented in the present disclosure. The method of any one of the first aspects of the examples.

The above method of the present disclosure has the following beneficial effects: using the noise reduction control method of the present disclosure, when the earphone is loosely worn, the filter parameters in the preset noise reduction filter can be adjusted in time to perform sound leakage compensation, so as to ensure Good noise reduction effect, improve user experience.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description serve to explain the principles of the invention.

1 is a schematic diagram of a noise-cancelling earphone according to an exemplary embodiment;

FIG. 2 is a flowchart illustrating a noise reduction control method according to an exemplary embodiment;

FIG. 3 is a flowchart illustrating a noise reduction control method according to an exemplary embodiment;

FIG. 4 is a flowchart showing a noise reduction control method according to an exemplary embodiment;

FIG. 5 is a flowchart illustrating a noise reduction control method according to an exemplary embodiment;

FIG. 6 is a flowchart showing a noise reduction control method according to an exemplary embodiment;

FIG. 7 is a flowchart showing a noise reduction control method according to an exemplary embodiment;

FIG. 8 is a block diagram of a noise reduction control device according to an exemplary embodiment;

Fig. 9 is a block diagram of a noise-cancelling earphone according to an exemplary embodiment.

Detailed ways

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. Where the following description refers to the drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the illustrative examples below are not intended to represent all implementations consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with some aspects of the invention as recited in the appended claims.

The "active noise reduction" of headphones corresponds to "passive noise reduction": passive noise reduction refers to the use of the shell to physically reduce the ambient noise transmitted to the human ear. All headphones have passive noise reduction; active noise reduction Noise reduction refers to actively generating sound waves with the opposite phase and the same or similar energy to the noise on the basis of passive noise reduction, and canceling part of the environmental noise through the interference phenomenon of the sound waves.

With the development of active noise reduction technology, noise reduction headphones have gradually become popular, and their frequency of use and duration of use have increased significantly. However, after wearing the headset for tens of minutes or even hours, the wearing will gradually loosen, and the fit between the headset and the ear will decrease, that is, the fit of the headset will gradually decrease with the user's daily activities. The noise reduction effect is closely related to the wearing state. When the wearing state changes, the noise reduction effect drops sharply.

In the prior art, due to the comprehensive consideration of chip cost and system stability, all noise-cancelling headphones are configured with fixed filters, that is, the active noise-cancelling filter cannot adjust parameters in real time to adapt to the wearing situation in real time. It is often difficult for users to wear it again and again in practice. Therefore, the increase in wearing time leads to a decrease in the noise reduction effect.

Fig. 1 is a schematic diagram of a noise reduction earphone according to an exemplary embodiment. As shown in Fig. 1 , the acoustic components mainly include: a feed-forward (Feed-Forward, FF) microphone 1, a feedback (Feed-Back, FB) Microphone 2, Speaker 3. The feedforward microphone 1 is placed outside the earphone to collect ambient noise in real time; the feedback microphone 2 is placed near the internal speaker of the earphone to detect the residual noise near the ear canal in real time. Feed-forward microphone 1, speaker 3, and feed-forward ANC chip 4 form a feed-forward ANC path 5; feedback microphone 2, speaker 3, and feedback ANC chip 6 form a feedback ANC path 7. The feedforward active noise reduction chip 4 and the feedback active noise reduction chip 6 are composed of a feedforward filter and a feedback filter implemented by hardware. The filter coefficients in the filter are rewritable parameters, and the corresponding coefficients need to be programmed before use.

In an exemplary embodiment of the present disclosure, a noise reduction control method is provided, which is applied to an earphone, and the earphone includes various earphone structures such as an in-ear earphone, a semi-in-ear earphone, and a headphone. FIG. 2 is a flowchart of a noise reduction control method according to an exemplary embodiment. As shown in FIG. 2 , the noise reduction control method includes the following steps:

Step S201, acquiring an environmental time-domain signal, wherein the environmental time-domain signal refers to a sound wave signal in the environment around the earphone represented by a time-domain representation;

Step S202, acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to an acoustic wave signal in the ear canal represented by a time domain representation method;

Step S203, if the environmental time domain signal and the ear canal time domain signal satisfy the preset filter parameter adjustment conditions, then determine the target noise reduction amount based on the environmental time domain signal and the ear canal time domain signal and the preset frequency response function;

Step S204, according to the preset noise reduction configuration information and the target noise reduction amount, determine the sound leakage compensation gear corresponding to the target noise reduction amount as the target sound leakage compensation gear, wherein the noise reduction configuration information is used to represent the noise reduction The corresponding relationship between the amount threshold and the sound leakage compensation gear, the noise reduction configuration information includes a plurality of noise reduction amount thresholds and the sound leakage compensation gear corresponding to each noise reduction amount threshold;

Step S205, determining target filter parameters based on the target sound leakage compensation gear;

Step S206: Adjust the filter parameters in the preset noise reduction filter to target filter parameters, wherein the noise reduction filter is used to perform noise reduction filtering processing on the input sound wave signal.

In step S201 and step S202, the environmental time domain signal is collected by the feedforward microphone, and the environmental time domain signal refers to the sound wave signal in the environment around the earphone represented by the time domain representation; the ear canal time domain signal is collected by the feedback microphone , the ear canal time domain signal refers to the sound wave signal in the ear canal represented by the time domain representation. The acquisition duration of the time domain signal can be set according to actual needs. In order to ensure the accuracy and timeliness of the signal, the acquisition duration is generally between 1 and 3 seconds, for example, 2 seconds. The sampling rate of the time domain signal can also be set according to actual needs. In order to collect the signal conveniently, the general signal sampling rate is at least 16kHz.

In step S203, when the earphone is an in-ear earphone, since the noise reduction effect is related to the fit of the earphone, when the earphone is in a fully fitted state, the active noise reduction effect is the best. It is not necessary to adjust the filter parameters; however, when the earphones are worn loosely, for example, when the user wears the earphones for a long time and the earphone and ear fit is low, the noise reduction effect will be poor. At this time, the filter parameters need to be adjusted to improve the The problem of poor noise reduction caused by poor fit. The adjustment conditions of the filter parameters are pre-stored in the earphone, and it is determined whether the adjustment conditions of the filter parameters are satisfied according to the environmental time domain signal and the ear canal time domain signal. When it is determined that the filter parameter adjustment conditions are met, the target noise reduction amount is determined based on the acquired environmental time domain signal and ear canal time domain signal and the preset frequency response function, and the target noise reduction amount is the reduction of the earphone in the current wearing state. The amount of noise can be obtained by any formula that can calculate the amount of noise reduction.

In step S204, the preset noise reduction configuration information is used to represent the corresponding relationship between the noise reduction amount threshold and the sound leakage compensation gear, and is pre-stored in the memory of the earphone, according to the noise reduction amount threshold to which the target noise reduction amount belongs. range, and determine the corresponding sound leakage compensation gear, which is the target sound leakage compensation gear. Different sound leakage compensation gears can be set according to different headphone structures. For example, the sound leakage compensation gears have a total of 0 to X gears. Different gears correspond to different earphone wearing slack. The degree of slack is getting looser and looser, that is, the fit between the earphone and the ear is getting worse and worse. The initial gear is 0, the initial gear is the gear when the earphone is worn with the highest fit, and the X gear is the fit of the earphone. the lowest gear. Each sound leakage compensation gear corresponds to a noise reduction threshold. For example, when the noise reduction threshold is 0, the corresponding noise reduction threshold is ε ₀ , that is, if the target noise reduction is greater than ε ₀ , the corresponding sound leakage compensation gear is 0. . The noise reduction configuration information includes a plurality of noise reduction amount thresholds and a sound leakage compensation gear corresponding to each noise reduction amount threshold. Due to the different noise reduction effects of different headphones, the corresponding relationship between the noise reduction threshold and the sound leakage compensation gear can be set according to different headphones, so as to be able to use different sound leakage compensation under different wearing slack. Increase the amount of noise reduction and improve the noise reduction effect.

In steps S205 and S206, different sound leakage compensation gears correspond to different filter parameters, and the target filter parameters are determined based on the sound leakage compensation gear corresponding to the target noise reduction amount, ie, the target sound leakage gear. Adjust the filter parameters in the preset noise reduction filter to the target filter parameters. The noise reduction filter is the main hardware structure of the noise reduction chip in the headphone structure. The filters in the headphone include feedforward filters and feedback filters. , which is used to perform noise reduction filtering processing on the input sound wave signal. The adjusted target filter parameters can increase the noise reduction amount and improve the noise reduction effect by means of sound leakage compensation. Here, it should be noted that, based on the principle of active noise reduction, increasing the noise reduction amount involved in this step refers to changing the gain of the output active noise signal used to cancel the external noise signal, or changing the gain used to offset the external noise signal. Filtering characteristics of a device for filtering active noise signals.

When adjusting the filter parameters, you can only adjust the filter parameters of the feedforward filter, or you can adjust the filter parameters of the feedforward filter and the filter parameters of the feedback filter at the same time. Since the feedback noise reduction effect is too strong, it may cause abnormal conditions such as whistling and equipment cavity resonance. Therefore, it is determined whether to adjust the filter parameters of the feedback filter according to the structure of the headset, such as the acoustic cavity structure of the headset and the performance of components. When adjusting the filter parameters of the feedforward filter and the filter parameters of the feedback filter at the same time, the noise reduction effect changes more obviously, and the adjusted noise reduction effect is better.

In an exemplary embodiment of the present disclosure, the environmental time domain signal and the ear canal time domain signal are acquired, and when the environmental time domain signal and the ear canal time domain signal satisfy the preset filter parameter adjustment conditions, based on the environmental time domain signal and the ear canal time domain signal The ear canal time domain signal is used to determine the target noise reduction amount. According to the corresponding relationship between the noise reduction amount threshold and the sound leakage compensation gear and the target noise reduction amount, the sound leakage compensation gear corresponding to the target noise reduction amount is determined as the target sound leakage. The compensation gear, based on the target sound leakage compensation gear, determines the target filter parameters, and adjusts the filter parameters in the preset noise reduction filter to the target filter parameters. The filter parameters in the noise reduction filter perform sound leakage compensation to ensure a good noise reduction effect and improve user experience.

In an exemplary embodiment of the present disclosure, a noise reduction control method is provided, which is applied to an earphone, and the earphone includes various earphone structures such as an in-ear earphone, a semi-in-ear earphone, and a headphone. FIG. 3 is a flowchart of a noise reduction control method according to an exemplary embodiment. As shown in FIG. 3 , the noise reduction control method includes the following steps:

Step S301, acquiring an environmental time domain signal, wherein the environmental time domain signal refers to a sound wave signal in the environment around the earphone represented by a time domain representation method;

Step S302, acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to an acoustic wave signal in the ear canal represented by a time domain representation method;

Step S303, based on the environmental time domain signal, determine the total energy of the environmental time domain signal, wherein the environmental time domain signal includes a plurality of frequency points, and the total energy of the environmental time domain signal refers to the sum of the energy of each frequency point in the environmental time domain signal ;

Step S304, based on the ear canal time domain signal, determine the total energy of the ear canal time domain signal, wherein the ear canal time domain signal includes a plurality of frequency points, and the total energy of the ear canal time domain signal refers to each frequency in the ear canal time domain signal. the sum of the energies of the points;

Step S305, if the ratio of the total energy of the environmental time domain signal to the total energy of the ear canal time domain signal is greater than or equal to a preset energy threshold, it is determined that the preset filter parameter adjustment conditions are met;

Step S306, if the environmental time domain signal and the ear canal time domain signal satisfy the preset filter parameter adjustment conditions, then determine the target noise reduction amount based on the environmental time domain signal and the ear canal time domain signal and the preset frequency response function;

Step S307, according to the preset noise reduction configuration information and the target noise reduction amount, determine the sound leakage compensation gear corresponding to the target noise reduction amount as the target sound leakage compensation gear, wherein the noise reduction configuration information is used to represent the noise reduction The corresponding relationship between the amount threshold and the sound leakage compensation gear, the noise reduction configuration information includes a plurality of noise reduction amount thresholds and the sound leakage compensation gear corresponding to each noise reduction amount threshold;

Step S308, determining target filter parameters based on the target acoustic leakage compensation gear;

Step S309: Adjust the filter parameters in the preset noise reduction filter to target filter parameters, wherein the noise reduction filter is used to perform noise reduction filtering processing on the input sound wave signal.

Steps S306 - S309 are the same as steps S203 - S206 , and steps S301 - S302 are the same as steps S201 - S202 , and will not be repeated here.

In step S303 and step S304, the total energy of the environmental time domain signal and the total energy of the ear canal time domain signal are determined respectively by the environmental time domain signal and the ear canal time domain signal. It should be noted that the order of steps S303 and S304 is not the same. make restrictions.

After obtaining the environmental time domain signal and the ear canal time domain signal, the environmental time domain signal and the ear canal time domain signal can be divided into frames and windowed, and the environmental time domain signal can be divided into multi-frame signals. The signal is divided into multi-frame signals, and in the subsequent correlation calculation, the frame-by-frame calculation is performed with each frame as the unit.

表示整数；n为单帧信号内的采样点索引，即第m帧信号的第n个采样点，n∈[0,N)且

表示整数。M和N根据信号采样率、应用平台等因素不同而变化。为了防止块效应，便于频域计算，帧与帧之间存在一部分重叠的采样点，即前一帧的尾部数据与下一帧头部数据相同，重叠比例记为δ，δ∈(0％,100％)。δ也会根据信号采样率等其他平台因素不同而改变。即在对环境时域信号和耳道时域信号进行分帧加窗处理时，具体为重叠加窗处理，相邻的窗之间存在重叠，重叠率为1/2。For example, a time domain signal (which may be an environmental time domain signal or an ear canal time domain signal) has a total of M frames, that is, after frame-by-frame windowing processing, it is divided into M windows. Each frame of signal has N sampling points in total, that is, when the time domain signal is sampled, each frame includes N time domain sampling points. The ambient time domain signal of the feedforward microphone is denoted as s _FF (m,n), and the ear canal time domain signal of the feedback microphone is denoted as s _FB (m,n). Among them, m is the frame index, that is, the mth frame signal in M frames in a time domain signal, m∈[0,M) and

Represents an integer; n is the sampling point index in a single frame signal, that is, the nth sampling point of the mth frame signal, n∈[0,N) and

Represents an integer. M and N vary according to the signal sampling rate, application platform and other factors. In order to prevent block effect and facilitate frequency domain calculation, there are some overlapping sampling points between frames, that is, the tail data of the previous frame is the same as the header data of the next frame, and the overlap ratio is recorded as δ, δ∈(0%, 100%). δ will also vary depending on other platform factors such as the signal sample rate. That is, when the ambient time domain signal and the ear canal time domain signal are subjected to frame-by-frame windowing processing, specifically overlapping windowing processing, there is overlap between adjacent windows, and the overlap rate is 1/2.

In an example, when the signal sampling rate is 16 kHz, let M=60, N=512, δ=50%. That is, in this example, a segment of acoustic signal with a sampling rate of 16 kHz is divided into 60 frames in the time domain after framed and windowed, and each frame contains 512 sampling points in the time domain. The coincidence rate of sample points between frames is 50%.

Since the frame-by-frame calculation is performed in units of each frame. Each frame of ambient time-domain signal includes multiple frequency points, that is, multiple sampling points. The total energy of each frame of ambient time-domain signal is the sum of the energy of each frequency point in the ambient time-domain signal, that is, the sum of the energy of each sampling point. and; each frame of ear canal time-domain signal includes multiple frequency points, that is, multiple sampling points, and the total energy of each frame of ear canal time-domain signal is the sum of the energy of each frequency point in the ear canal time-domain signal, that is, each The sum of the energies of the sampling points. After calculating the total energy of each frame, the sum of the energy of all frames is added to obtain the total energy of the ambient time domain signal and the total energy of the ear canal time domain signal. The total energy of the environmental time domain signal, denoted as E _FF , the total energy of the ear canal time domain signal, denoted as E _FB , then:

Among them, s _FB (m,n)—ear canal time domain signal;

s _FF (m,n)—environmental time domain signal;

M—the number of frame signals obtained after the time domain signal is framed and windowed;

N—the number of time domain sampling points contained in each frame of signal;

m—the mth frame in M frames;

n—the nth sampling point among the N time domain sampling points.

In step S305, the energy ratio is obtained according to the total energy E _FF of the environmental time domain signal and the total energy E _FB of the ear canal time domain signal, and the energy ratio is denoted as θ, then:

The preset energy threshold is the threshold of the ratio of the total energy of the environmental time domain signal to the total energy of the ear canal time domain signal, and whether the preset filter parameter adjustment conditions are met is determined by the preset energy threshold. The total energy of the ambient time domain signal and the total energy of the ear canal time domain signal can reflect the current use state of the headset, including touching the headset, strenuous exercise, and playing the sound source volume too loudly. stable, the filter parameters will also be unstable and do not need to be adjusted at this time. The correlation between the total energy of the ear canal time domain signal and the use state is greater than the correlation between the total energy of the ambient time domain signal and the use state. When the use state is unstable, the total energy of the ear canal time domain signal will rise more than the total energy of the ambient time domain signal. The increase in energy, the energy ratio will become smaller at this time. Therefore, when the energy ratio is greater than or equal to the preset energy threshold, it is determined that the preset filter parameter adjustment conditions are met; when the energy ratio is less than the preset energy threshold, the use state is unstable, and it is determined that the preset filter is not satisfied. conditions for adjusting the parameters of the controller.

For example, the preset energy threshold is recorded as θ ₀ . When θ≥θ ₀ , the preset filter parameter adjustment conditions are satisfied; when θ<θ ₀ , the preset filter parameter adjustment conditions are not met. In an example, the preset energy threshold θ ₀ =1/3, and the value of the preset energy threshold can be adjusted according to the actual situation and different earphone devices to which the method in this embodiment is applied. Moreover, the preset energy threshold may be determined by multiple tests before the earphone leaves the factory, or may be determined and stored in the earphone according to an empirical value.

In an exemplary embodiment of the present disclosure, when it is determined that the preset filter parameter adjustment conditions are met, the filter Adjusting the parameters of the filter can ensure that the use state of the headset is stable at this time, and avoid frequent adjustment of filter parameters due to unstable use state, which brings a poor listening experience to the user.

In an exemplary embodiment of the present disclosure, a noise reduction control method is provided, which is applied to an earphone, and the earphone includes various earphone structures such as an in-ear earphone, a semi-in-ear earphone, and a headphone. FIG. 4 is a flowchart of a noise reduction control method according to an exemplary embodiment. As shown in FIG. 4 , the noise reduction control method includes the following steps:

Step S401, acquiring an environmental time domain signal, wherein the environmental time domain signal refers to a sound wave signal in the environment around the earphone represented by a time domain representation method;

Step S402, acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to an acoustic wave signal in the ear canal represented by a time domain representation method;

Step S403, if the environmental time domain signal and the ear canal time domain signal satisfy the preset filter parameter adjustment conditions, perform Fourier transform on the environmental time domain signal and the ear canal time domain signal respectively to obtain the environmental frequency domain signal and the ear canal time domain signal. Frequency domain signal, wherein the environmental frequency domain signal refers to the sound wave signal in the surrounding environment of the earphone represented by the frequency domain representation, and the ear canal frequency domain signal refers to the ear canal represented by the frequency domain representation. The acoustic signal in the channel;

Step S404, based on the environmental frequency domain signal, the ear canal frequency domain signal and the preset frequency response function, obtain a crossover frequency response, and the crossover frequency response is related to the frequency point;

Step S405, obtaining a reference noise reduction amount according to the cross frequency response;

Step S406, obtain the average noise reduction amount of the target frequency band according to the reference noise reduction amount, and determine the average noise reduction amount as the target noise reduction amount, wherein the average noise reduction amount refers to each frequency point in the target frequency band The average value of the energy;

Step S407, according to the preset noise reduction configuration information and the target noise reduction amount, determine the sound leakage compensation gear corresponding to the target noise reduction amount as the target sound leakage compensation gear, wherein the noise reduction configuration information is used to represent the noise reduction The corresponding relationship between the amount threshold and the sound leakage compensation gear, the noise reduction configuration information includes a plurality of noise reduction amount thresholds and the sound leakage compensation gear corresponding to each noise reduction amount threshold;

Step S408, determining target filter parameters based on the target acoustic leakage compensation gear;

Step S409: Adjust the filter parameters in the preset noise reduction filter to target filter parameters, wherein the noise reduction filter is used to perform noise reduction filtering processing on the input sound wave signal.

Steps S401 - S402 are the same as steps S201 - S202 , and steps S407 - S409 are the same as steps S204 - S206 , and will not be repeated here.

In step S403, when the environmental time domain signal and the ear canal time domain signal satisfy the preset filter parameter adjustment conditions, Fourier transform is performed on the environmental time domain signal and the ear canal time domain signal respectively. The ambient frequency domain signal and the ear canal frequency domain signal are obtained using the fast Fourier transform, namely the discrete Fourier transform. The environmental frequency domain signal refers to the sound wave signal in the surrounding environment of the earphone represented by the frequency domain representation, and the ear canal frequency domain signal refers to the sound wave signal in the ear canal represented by the frequency domain representation. Before performing the fast Fourier transform, in order to reduce the leakage error, a window function is superimposed on the ambient time domain signal and the ear canal time domain signal respectively. The window function can be selected according to actual needs, for example, using a Blackman-Harris window. .

The ambient time domain signal is denoted as s _FF (m,n), the ear canal time domain signal is denoted as s _FB (m,n), the window function is denoted as w(n), and the ambient frequency domain signal is denoted as S _FF (m,k ), the ear canal frequency domain signal is denoted as S _FB (m,k), then:

为离散傅里叶变换运算，k为傅里叶变换的尺度，即进行傅里叶变换后会生成k个频点的频谱，k的值可以根据实际需求设定，例如每帧时域信号中包括N个信号采样点时，k＝N。S_FF(m,k)和S_FB(m,k)表示第m个帧中的第k个频点的频域信号。当然，可以理解的是，根据需求可以对傅里叶变换的尺度k进行调整，当k的取值越大时，经过傅里叶变换后频谱中的频点的数量越多，对声音信号在频域上的分析越精确。in,

For the discrete Fourier transform operation, k is the scale of the Fourier transform, that is, the spectrum of k frequency points will be generated after the Fourier transform, and the value of k can be set according to actual needs, such as in the time domain signal of each frame. When including N signal sampling points, k=N. S _FF (m, k) and S _FB (m, k) represent the frequency domain signal of the k th frequency point in the m th frame. Of course, it can be understood that the scale k of the Fourier transform can be adjusted according to the requirements. When the value of k is larger, the number of frequency points in the spectrum after the Fourier transform is greater, and the sound signal is in the The analysis in the frequency domain is more accurate.

In step S404, based on the environmental frequency domain signal, the ear canal frequency domain signal and the preset frequency response function, a crossover frequency response is obtained, and the crossover frequency response is related to a frequency point.

The three cross-frequency responses of the kth frequency point are denoted as H ₀ (k), H ₁ (k) and H ₂ (k) respectively, then:

表示求复数实部，

表示求复数虚部；in,

means to find the real part of a complex number,

means to find the imaginary part of a complex number;

s _FB (m,n)—ear canal time domain signal; S _FF (m,k)—environmental frequency domain signal; S _FB (m,k)—ear canal frequency domain signal;

M—the number of frame signals obtained after the time domain signal is framed and windowed;

m—the mth frame in M frames;

k—the kth frequency point in the mth frame;

n—the nth sampling point among the N time domain sampling points.

In step S405, the reference noise reduction amount is obtained according to the cross frequency response, and the reference noise reduction amount of the kth frequency point is denoted as H(k), then:

where H(k) is in dB.

In step S406, the average noise reduction amount of the target frequency band is obtained according to the reference noise reduction amount, and the average noise reduction amount is determined as the target noise reduction amount. The average noise reduction amount refers to the average value of the energy of each frequency point in the target frequency band, and the target frequency band is the maximum noise reduction depth frequency band of the audio device, for example, between 50 and 300 Hz. The target noise reduction amount in this frequency band is recorded as ε, then:

Among them, the unit of ε is dB, k ₀ and k ₁ are the frequency points closest to 50Hz and 300Hz in the spectrum of k frequency points, which can be fine-tuned according to actual needs. The average value of noise reduction of all frequency points in the target frequency band is the target noise reduction amount. For example, when the spectrum obtained after Fourier transform includes spectral lines of 50 Hz and 300 Hz, then k ₀ is 50 Hz, and k ₁ is 100 Hz. For another example, when the spectrum obtained after Fourier transform does not include the spectral lines of 50Hz and 300Hz, but includes the spectral lines of 49Hz, 49Hz, 52Hz, 280Hz, 298Hz, and 306Hz, then k ₀ is 49 Hz, and k ₁ is 298Hz. Since the discrete Fourier transform is performed on the time-domain signal and the time-domain signal is converted into a frequency-domain signal, the transform scales used are different, which will lead to different total number of frequency points in the spectrum, and the physical frequency corresponding to each frequency point is also different. Different, in the actual implementation process k ₀ , k ₁ and the noise reduction evaluation frequency band (that is, the target frequency band) can be fine-tuned according to the earphone situation

In an exemplary embodiment of the present disclosure, a noise reduction control method is provided, which is applied to an earphone, and the earphone includes various earphone structures such as an in-ear earphone, a semi-in-ear earphone, and a headphone. Fig. 5 is a flowchart showing a noise reduction control method according to an exemplary embodiment. As shown in Fig. 5, the noise reduction control method includes the following steps:

Step S501, acquiring an environmental time domain signal, wherein the environmental time domain signal refers to a sound wave signal in the environment around the earphone represented by a time domain representation method;

Step S502, acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to an acoustic wave signal in the ear canal represented by a time domain representation method;

Step S503, if the environmental time domain signal and the ear canal time domain signal satisfy the preset filter parameter adjustment conditions, then determine the target noise reduction amount based on the environmental time domain signal and the ear canal time domain signal and the preset frequency response function;

Step S504, obtain a preset noise reduction threshold set, the preset noise reduction threshold set includes a plurality of noise parameter values arranged from small to large, and the plurality of noise parameter values constitute a plurality of noise reduction amount thresholds, and the noise reduction amount threshold is related to all noise reduction thresholds. Corresponding to the sound leakage compensation gear;

Step S505, according to the target noise reduction amount and the preset noise reduction threshold set, determine the noise reduction amount threshold to which the target noise reduction amount belongs;

Step S506, according to the noise reduction amount threshold to which the target noise reduction amount belongs, determine the sound leakage compensation gear position corresponding to the noise reduction amount threshold to which the target noise reduction amount belongs as the target sound leakage compensation gear;

Step S507, determining target filter parameters based on the target sound leakage compensation gear;

Step S508: Adjust the filter parameters in the preset noise reduction filter to target filter parameters, wherein the noise reduction filter is used to perform noise reduction filtering processing on the input sound wave signal.

The contents of steps S501-S503 are the same as those of step S201-step S203, and the contents of steps S507-step S508 are the same as those of steps S205-step S206, which will not be repeated here.

In step S504, according to the noise reduction effect of the earphone, a plurality of noise reduction threshold sets are obtained, and different earphone devices have different noise reduction threshold sets. A plurality of noise reduction threshold sets are preset in the earphone, the preset noise reduction threshold set includes a plurality of noise parameter values arranged from small to large, and the plurality of noise parameter values constitute a plurality of noise reduction thresholds, and the noise reduction thresholds Corresponds to the sound leakage compensation gear.

X表示声泄漏补偿档位的档位个数，ε₁,ε₂,…,ε_X表示需要降低对应的档位，ε_-X+1,…,ε_-2,ε_-1表示需要提升档位，档位和档位个数根据耳机的佩戴状态确定，可以根据实际需求设定，从第0档到第X档适用的佩戴状况为由紧至松。该降噪阈值集合预存在耳机中，降噪阈值集合通过已经建立的声学模型获得，在实施过程中，根据耳机的应用场景不同，可以对降噪阈值集合进行调整。For example, the set of noise reduction thresholds is denoted as {ε _-X+1 ,…,ε _-2 ,ε _-1 ,ε ₀ ,ε ₁ ,ε ₂ ,…,ε _X },

X represents the number of gears of the sound leakage compensation gear, ε ₁ ,ε ₂ ,…,ε _X indicates that the corresponding gear needs to be lowered, ε _-X+1 ,…,ε _-2 ,ε _-1 indicates that the gear needs to be increased The position, gear and number of gears are determined according to the wearing state of the headset, and can be set according to actual needs. The applicable wearing conditions from gear 0 to gear X are from tight to loose. The noise reduction threshold set is pre-stored in the earphone, and the noise reduction threshold set is obtained through the established acoustic model. During the implementation process, according to different application scenarios of the earphone, the noise reduction threshold set can be adjusted.

In step S505 and step S506, according to the target noise reduction amount and the preset noise reduction threshold set, determine the noise reduction amount threshold to which the target noise reduction amount belongs, and obtain the target noise reduction amount according to the noise reduction amount threshold to which the target noise reduction amount belongs The corresponding sound leakage compensation gear.

For example, the target noise reduction amount is recorded as ε, when ε<ε ₀ , it means that the wearing state is loose, the noise reduction amount is low, and the gear needs to be increased; when ε _-1 ≤ε<ε ₀ , it is increased by one gear; When ε _-2 ≤ε<ε _-1 , increase by two gears; and so on, when ε<ε _-X+1 , increase X gear. If the sum of the number of gears to be raised and the current number of gears is greater than the maximum number of gears X, directly upgrade to the Xth gear. For example, the maximum number of gears is 8, the current number of gears is 4, and the number of gears to be upgraded is 5. If the number of gears exceeds the maximum number of gears of 8, it is also directly upgraded to the maximum number of gears of 8. When ε>ε ₁ , it indicates that the amount of noise reduction is too high. In order to reduce ear pressure and maintain auditory comfort, it is necessary to lower the gear; when ε ₁ ≤ε<ε ₂ , lower the gear by one _; When it is ₃ , reduce it by two gears; and so on, when ε>ε _X , reduce the X gear. If the difference between the current number of gears and the number of gears to be lowered is less than zero, it is directly lowered to the 0th gear.

In an exemplary embodiment of the present disclosure, a noise reduction control method is provided, which is applied to an earphone, and the earphone includes various earphone structures such as an in-ear earphone, a semi-in-ear earphone, and a headphone. FIG. 6 is a flowchart of a noise reduction control method according to an exemplary embodiment. As shown in FIG. 6 , the noise reduction control method includes the following steps:

Step S601, acquiring an environmental time-domain signal, wherein the environmental time-domain signal refers to a sound wave signal in the surrounding environment of the earphone represented by a time-domain representation;

Step S602, acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to an acoustic wave signal in the ear canal represented by a time domain representation method;

Step S603, if the environmental time domain signal and the ear canal time domain signal satisfy the preset filter parameter adjustment conditions, then determine the target noise reduction amount based on the environmental time domain signal and the ear canal time domain signal and the preset frequency response function;

Step S604, according to the preset noise reduction configuration information and the target noise reduction amount, determine the sound leakage compensation gear corresponding to the target noise reduction amount as the target sound leakage compensation gear, wherein the noise reduction configuration information is used to represent the noise reduction The corresponding relationship between the amount threshold and the sound leakage compensation gear, the noise reduction configuration information includes a plurality of noise reduction amount thresholds and the sound leakage compensation gear corresponding to each noise reduction amount threshold;

Step S605, acquiring chip configuration information, where the chip configuration information is used to represent whether the filter coefficients stored in the chip support updating;

If the filter coefficient stored in the chip supports updating, step S606 is performed; if the filter system stored in the chip does not support updating, step S607 is performed.

Step S606, determining the target filter coefficient based on the target sound leakage compensation gear, and adjusting the filter coefficient in the preset noise reduction filter to the target filter coefficient;

Step S607: Determine the target filter gain based on the target sound leakage compensation gear, and adjust the filter gain in the preset noise reduction filter to the target filter gain. The contents of steps S601 to S604 are the same as those of steps S201 to S204, and are not repeated here.

In step S605, after the sound leakage compensation gear is determined, the chip configuration information is obtained, and the chip configuration information is used to indicate whether the filter coefficients stored in the chip support updating. Different headsets use different active noise reduction chips, and different chips support different filter coefficient updates. By obtaining the chip configuration information, it is determined whether the chip used in the headset supports filter coefficient update.

In steps S606 and S607, when the chip supports the update of filter coefficients, the target filter coefficients are determined based on the target sound leakage compensation gear, and the filter coefficients in the preset noise reduction filter are adjusted to the target filter coefficients ; When the filter system stored in the chip does not support updating, determine the target filter gain based on the target sound leakage compensation gear, and adjust the filter gain in the preset noise reduction filter to the target filter gain. Since updating the filter coefficients can also change the filter gain and filter phase, it is determined whether to update the filter coefficients or the filter gain according to whether the chip supports updating the filter coefficients.

When adjusting the filter parameters, only the filter parameters in the feedforward filter can be updated, or the filter parameters in the feedforward filter and the filter parameters in the feedback filter can be updated at the same time.

当芯片支持更新滤波器系数，且同时更新前馈滤波器中的滤波器参数和反馈滤波器中的滤波器参数时，记为

当芯片不支持更新滤波器系数，且只更新前馈滤波器中的滤波器参数时，记为

当芯片不支持更新滤波器系数，且同时更新前馈滤波器中的滤波器参数和反馈滤波器中的滤波器参数时，记为

其中，c表示滤波器系数，g表示滤波器增益，x代表当前档位，X代表最大档位。When the chip supports updating filter coefficients and only updates the filter parameters in the feedforward filter, it is recorded as

When the chip supports updating the filter coefficients, and at the same time updating the filter parameters in the feedforward filter and the filter parameters in the feedback filter, it is recorded as

When the chip does not support updating the filter coefficients and only updates the filter parameters in the feedforward filter, it is recorded as

When the chip does not support updating the filter coefficients, and the filter parameters in the feedforward filter and the filter parameters in the feedback filter are updated at the same time, it is recorded as

Among them, c represents the filter coefficient, g represents the filter gain, x represents the current gear, and X represents the maximum gear.

In an exemplary embodiment of the present disclosure, a noise reduction control method is provided, which is applied to an earphone, and the earphone includes various earphone structures such as an in-ear earphone, a semi-in-ear earphone, and a headphone. FIG. 7 is a flowchart of a noise reduction control method according to an exemplary embodiment. As shown in FIG. 7 , the noise reduction control method includes the following steps:

Step S701, acquiring an environmental time-domain signal, wherein the environmental time-domain signal refers to a sound wave signal in the environment around the earphone represented by a time-domain representation;

Step S702, acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to an acoustic wave signal in the ear canal represented by a time domain representation method;

Step S703, based on the environmental time domain signal, determine the total energy of the environmental time domain signal, wherein the environmental time domain signal includes a plurality of frequency points, and the total energy of the environmental time domain signal refers to the sum of the energy of each frequency point in the environmental time domain signal ;

Step S704, based on the ear canal time domain signal, determine the total energy of the ear canal time domain signal, wherein the ear canal time domain signal includes a plurality of frequency points, and the total energy of the ear canal time domain signal refers to each frequency in the ear canal time domain signal. the sum of the energies of the points;

Step S705, determining whether the preset filter parameter adjustment conditions are met;

If the ratio of the total energy of the environmental time-domain signal to the total energy of the ear canal time-domain signal is greater than or equal to the preset energy threshold, it is determined that the preset filter parameter adjustment conditions are met, and step S706 is executed; when it is determined that the preset filter parameter adjustment conditions are not met When the controller parameter adjustment conditions are met, the process ends.

In step S706, Fourier transform is performed on the environmental time domain signal and the ear canal time domain signal respectively, to obtain the environmental frequency domain signal and the ear canal frequency domain signal, wherein the environmental frequency domain signal refers to the signal in the frequency domain representation. represents the sound wave signal in the surrounding environment of the earphone, and the ear canal frequency domain signal refers to the sound wave signal in the ear canal represented by the frequency domain representation;

Step S707, based on the environmental frequency domain signal, the ear canal frequency domain signal and the preset frequency response function, obtain a crossover frequency response, and the crossover frequency response is related to the frequency point;

Step S708, obtaining a reference noise reduction amount according to the cross frequency response;

Step S709, obtain the average noise reduction amount of the target frequency band according to the reference noise reduction amount, and determine the average noise reduction amount as the target noise reduction amount, wherein the average noise reduction amount refers to each frequency point in the target frequency band The average value of the energy;

Step S710, obtain a preset noise reduction threshold set, the preset noise reduction threshold set includes a plurality of noise parameter values arranged from small to large, and the plurality of noise parameter values constitute a plurality of noise reduction thresholds, and the noise reduction threshold is related to all noise reduction thresholds. Corresponding to the sound leakage compensation gear;

Step S711, according to the target noise reduction amount and the preset noise reduction threshold set, determine the noise reduction amount threshold to which the target noise reduction amount belongs;

Step S5712, according to the noise reduction amount threshold to which the target noise reduction amount belongs, determine the sound leakage compensation gear position corresponding to the noise reduction amount threshold to which the target noise reduction amount belongs as the target sound leakage compensation gear;

Step S6713, acquiring chip configuration information, where the chip configuration information is used to represent whether the filter coefficients stored in the chip support updating;

If the filter coefficient stored in the chip supports updating, step S714 is performed; if the filter system stored in the chip does not support updating, step S715 is performed.

Step S714, determining the target filter coefficient based on the target sound leakage compensation gear, and adjusting the filter coefficient in the preset noise reduction filter to the target filter coefficient;

Step S715: Determine the target filter gain based on the target sound leakage compensation gear, and adjust the filter gain in the preset noise reduction filter to the target filter gain. Wherein, the filter parameters in the preset noise reduction filter include: filter parameters in the feedforward filter; or, filter parameters in the feedforward filter and filter parameters in the feedback filter.

It should be noted that, in order to adapt the earphone to the wearing state of the user at all times, the above-mentioned noise reduction control method is repeatedly performed at preset time intervals, for example, at time intervals of 30s˜120s.

In an exemplary embodiment of the present disclosure, the environmental time domain signal and the ear canal time domain signal are obtained, and according to the ratio of the total energy of the environmental time domain signal of the environmental time domain signal to the ear canal time domain signal ratio of the total energy of the ear canal time domain signal, Determine whether it is currently in a stable state of use to determine whether the preset filter parameter adjustment conditions are met, determine the target noise reduction amount based on the environmental time domain signal and the ear canal time domain signal, and compensate the gear according to the noise reduction threshold and sound leakage. The corresponding relationship between the target noise reduction amount and the target noise reduction amount, the sound leakage compensation gear corresponding to the target noise reduction amount is obtained, that is, the target sound leakage compensation gear. Based on the target sound leakage compensation gear, the target filter parameters are determined, and the preset The filter parameters in the noise reduction filter are adjusted to the target filter parameters. When the headphones are loosely worn, the filter parameters in the preset filter can be adjusted in time for sound leakage compensation, so as to improve the noise reduction and ensure good noise reduction. Noise effect, improve user experience.

In an exemplary embodiment of the present disclosure, a noise reduction control device is provided, which is applied to an earphone. FIG. 8 is a block diagram of a noise reduction control apparatus according to an exemplary embodiment. As shown in FIG. 8 , the noise reduction control apparatus includes:

The first obtaining module 801 is configured to obtain an environmental time-domain signal, wherein the environmental time-domain signal refers to a sound wave signal in the surrounding environment of the earphone represented by a time-domain representation;

The second acquiring module 802 is configured to acquire the ear canal time domain signal, wherein the ear canal time domain signal refers to the acoustic wave signal in the ear canal represented by the time domain representation;

The first determination module 803 is configured to, if the environmental time domain signal and the ear canal time domain signal satisfy a preset filter parameter adjustment condition, based on the environmental time domain signal and the ear canal time domain signal and the preset frequency response function to determine the target noise reduction amount;

The second determination module 804 is configured to, according to the preset noise reduction configuration information and the target noise reduction amount, determine the sound leakage compensation gear corresponding to the target noise reduction amount as the target sound leakage compensation gear, wherein , the noise reduction configuration information is used to represent the corresponding relationship between the noise reduction amount threshold and the sound leakage compensation gear, the noise reduction configuration information includes a plurality of noise reduction amount thresholds and the corresponding noise reduction amount thresholds sound leakage compensation gear;

The third determination module 805 is configured to determine target filter parameters based on the target sound leakage compensation gear;

The adjustment module 806 is configured to adjust the filter parameters in the preset noise reduction filter to the target filter parameters, wherein the noise reduction filter is used to perform noise reduction filtering processing on the input sound wave signal.

In an exemplary embodiment, the first determining module 803 is further configured to:

Determine the total energy of the environmental time domain signal based on the environmental time domain signal, wherein the environmental time domain signal includes a plurality of frequency points, and the total energy of the environmental time domain signal refers to each frequency in the environmental time domain signal the sum of the energies of the points;

Based on the ear canal time domain signal, the total energy of the ear canal time domain signal is determined, wherein the ear canal time domain signal includes a plurality of frequency points, and the total energy of the ear canal time domain signal refers to the time of the ear canal The sum of the energy of each frequency point in the domain signal;

If the ratio of the total energy of the environmental time domain signal to the total energy of the ear canal time domain signal is greater than or equal to a preset energy threshold, it is determined that the preset filter parameter adjustment conditions are met.

In an exemplary embodiment, the first determining module 803 is further configured to:

Fourier transform is performed on the environmental time domain signal and the ear canal time domain signal respectively to obtain the environmental frequency domain signal and the ear canal frequency domain signal, wherein the environmental frequency domain signal refers to the frequency domain representation The represented sound wave signal in the surrounding environment of the earphone, the ear canal frequency domain signal refers to the sound wave signal in the ear canal represented by the frequency domain representation;

obtaining a cross frequency response based on the ambient frequency domain signal and the ear canal frequency domain signal and a preset frequency response function, where the cross frequency response is related to a frequency point;

obtaining a reference noise reduction amount according to the cross frequency response;

According to the reference noise reduction amount, the average noise reduction amount of the target frequency band is obtained, and the average noise reduction amount is determined as the target noise reduction amount, wherein the average noise reduction amount refers to the average noise reduction amount in the target frequency band. The average value of the energy of each frequency point.

In an exemplary embodiment, the second determining module 804 is further configured to:

Obtain a preset noise reduction threshold set, where the preset noise reduction threshold set includes a plurality of noise parameter values arranged from small to large, and a plurality of the noise parameter values constitute a plurality of noise reduction amount thresholds, and the noise reduction amount The threshold value corresponds to the sound leakage compensation gear;

determining the noise reduction threshold to which the target noise reduction belongs according to the target noise reduction and the preset noise reduction threshold set;

According to the noise reduction amount threshold to which the target noise reduction amount belongs, the sound leakage compensation gear position corresponding to the noise reduction amount threshold to which the target noise reduction amount belongs is determined as the target sound leakage compensation gear position.

In an exemplary embodiment, the third determining module 805 is further configured to:

acquiring chip configuration information, where the chip configuration information is used to represent whether the filter coefficients stored in the chip support updating;

If the filter coefficients stored in the chip support updating, determine the target filter coefficients based on the target sound leakage compensation gear, and adjust the filter coefficients in the preset noise reduction filter to the target filter coefficients ;

If the filter system stored in the chip does not support updating, determine the target filter gain based on the target sound leakage compensation gear, and adjust the filter gain in the preset noise reduction filter to the target filter gain.

In an exemplary embodiment, the filter parameters in the preset noise reduction filter include:

the filter parameters in the feedforward filter; or,

Filter parameters in feedforward filters and filter parameters in feedback filters.

Regarding the apparatus in the above-mentioned embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be described in detail here.

The present disclosure also provides a noise reduction earphone, on which the above-mentioned noise reduction control device is arranged to realize the noise reduction control method in the above embodiment. FIG. 9 is a block diagram of a noise-cancelling earphone 900 according to an exemplary embodiment.

9, noise-cancelling headphones 900 may include one or more of the following components: a processing component 902, a memory 904, a power supply component 906, a multimedia component 908, an audio component 910, an input/output (I/O) interface 912, a sensor component 914 , and communication component 916 .

The processing component 902 generally controls the overall operation of the noise-cancelling headset 900, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 902 may include one or more processors 920 to execute instructions to perform all or some of the steps of the methods described above. Additionally, processing component 902 may include one or more modules to facilitate interaction between processing component 902 and other components. For example, processing component 902 may include a multimedia module to facilitate interaction between multimedia component 908 and processing component 902.

Memory 904 is configured to store various types of data to support operation in noise-cancelling headphones 900 . Examples of such data include instructions for any application or method operating on the noise-cancelling headset 900, contact data, phonebook data, messages, pictures, videos, and the like. Memory 904 may be implemented by any type of volatile or non-volatile storage 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.

Power supply assembly 906 provides power to the various components of noise-cancelling earphone 900 . Power supply components 906 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to noise-cancelling headphones 900 .

Multimedia component 908 includes a screen that provides an output interface between the noise-cancelling headphones 900 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from a user. The touch panel includes one or more touch sensors to sense touch, swipe, and gestures on the touch panel. The touch sensor may not only sense the boundaries of a touch or swipe action, but also detect the duration and pressure associated with the touch or swipe action. In some embodiments, the multimedia component 908 includes a front-facing camera and/or a rear-facing camera. When the noise-cancelling earphone 900 is in an operation mode, such as a shooting mode or a video mode, the front camera and/or the rear camera may receive external multimedia data. Each of the front and rear cameras can be a fixed optical lens system or have focal length and optical zoom capability.

Audio component 910 is configured to output and/or input audio signals. For example, audio component 910 includes a microphone (MIC) that is configured to receive external audio signals when noise-cancelling headset 900 is in operating modes, such as calling mode, recording mode, and voice recognition mode. The received audio signal may be further stored in memory 904 or transmitted via communication component 916 . In some embodiments, audio component 910 also includes a speaker for outputting audio signals.

The I/O interface 912 provides an interface between the processing component 902 and a peripheral interface module, which may be a keyboard, a click wheel, a button, or the like. These buttons may include, but are not limited to: home button, volume buttons, start button, and lock button.

Sensor assembly 914 includes one or more sensors for providing status assessment of various aspects of noise-cancelling headphones 900 . For example, the sensor assembly 914 can detect the on/off state of the noise-cancelling headphones 900, the relative positioning of the components, such as the display and keypad of the noise-cancelling headphones 900, and the sensor assembly 914 can also detect the noise-cancelling headphones 900 or drop A change in the position of a component of the noise-cancelling headset 900 , the presence or absence of user contact with the noise-cancelling headset 900 , the orientation or acceleration/deceleration of the noise-cancelling headset 900 , and the temperature change of the noise-cancelling headset 900 . Sensor assembly 914 may include a proximity sensor configured to detect the presence of nearby objects in the absence of any physical contact. Sensor assembly 914 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 914 may also include an acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

Communication component 916 is configured to facilitate wired or wireless communication between noise-cancelling headset 900 and other devices. Noise-cancelling headphones 900 can access wireless networks based on communication standards, such as WiFi, 2G or 3G, or a combination thereof. In one exemplary embodiment, the communication component 916 receives broadcast signals or broadcast related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 916 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

In an exemplary embodiment, noise-cancelling headphones 900 may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field Programmable gate array (FPGA), controller, microcontroller, microprocessor or other electronic component implementation for carrying out the above method.

In an exemplary embodiment, there is also provided a non-transitory computer-readable storage medium including instructions, such as memory 904 including instructions, executable by the processor 920 of the noise-cancelling headset 900 to accomplish the above method. For example, the non-transitory computer-readable storage medium may be ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like.

A non-transitory computer-readable storage medium on which computer program instructions are stored, characterized in that, when the computer program instructions are invoked by a processor, the method described in any one of the foregoing embodiments is executed.

Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or conventional techniques in the art not disclosed by this disclosure . The specification and examples are to be regarded as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

It should be understood that the present invention is not limited to the precise structures described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims (9)

1. A noise reduction control method is applied to earphones, and the method comprises the following steps:

acquiring an environment time domain signal, wherein the environment time domain signal refers to a sound wave signal in the surrounding environment of the earphone expressed by adopting a time domain expression mode;

acquiring an ear canal time domain signal, wherein the ear canal time domain signal refers to a sound wave signal in an ear canal expressed by adopting a time domain expression mode;

if the environment time domain signal and the ear canal time domain signal meet a preset filter parameter adjusting condition, determining a target noise reduction amount based on the environment time domain signal, the ear canal time domain signal and a preset frequency response function;

determining an acoustic leakage compensation gear corresponding to the target noise reduction amount as a target acoustic leakage compensation gear according to preset noise reduction configuration information and the target noise reduction amount, wherein the noise reduction configuration information is used for representing the corresponding relation between noise reduction amount thresholds and acoustic leakage compensation gears, and the noise reduction configuration information comprises a plurality of noise reduction amount thresholds and acoustic leakage compensation gears corresponding to each noise reduction amount threshold;

determining a target filter parameter based on the target acoustic leakage compensation gear;

and adjusting filter parameters in a preset noise reduction filter to the target filter parameters, wherein the noise reduction filter is used for carrying out noise reduction filtering processing on the input sound wave signals.

2. The noise reduction control method according to claim 1, characterized by further comprising: judging whether the environment time domain signal and the ear canal time domain signal meet preset filter parameter adjustment conditions by adopting the following method:

determining the total energy of the environmental time domain signal based on the environmental time domain signal, wherein the environmental time domain signal comprises a plurality of frequency points, and the total energy of the environmental time domain signal refers to the sum of the energy of each frequency point in the environmental time domain signal;

determining the total energy of the ear canal time domain signal based on the ear canal time domain signal, wherein the ear canal time domain signal comprises a plurality of frequency points, and the total energy of the ear canal time domain signal refers to the sum of the energy of each frequency point in the ear canal time domain signal;

and if the ratio of the total energy of the environment time domain signal to the total energy of the ear canal time domain signal is greater than or equal to a preset energy threshold value, judging that a preset filter parameter adjusting condition is met.

3. The method of claim 1, wherein the determining a target noise reduction amount based on the ambient time domain signal and the ear canal time domain signal and a preset frequency response function comprises:

performing Fourier transform on the environment time domain signal and the ear canal time domain signal respectively to obtain an environment frequency domain signal and an ear canal frequency domain signal, wherein the environment frequency domain signal refers to a sound wave signal in the surrounding environment of the earphone represented by a frequency domain representation mode, and the ear canal frequency domain signal refers to a sound wave signal in the ear canal represented by a frequency domain representation mode;

obtaining a cross frequency response based on the environment frequency domain signal, the ear canal frequency domain signal and a preset frequency response function, wherein the cross frequency response is related to a frequency point;

obtaining a reference noise reduction quantity according to the cross frequency response;

and obtaining an average noise reduction amount of a target frequency band according to the reference noise reduction amount, and determining the average noise reduction amount as the target noise reduction amount, wherein the average noise reduction amount refers to an average value of energy of each frequency point in the target frequency band.

4. The noise reduction control method according to claim 1, wherein the determining, as a target acoustic leakage compensation step, an acoustic leakage compensation step corresponding to the target noise reduction amount according to preset noise reduction configuration information and the target noise reduction amount includes:

acquiring a preset noise reduction threshold value set, wherein the preset noise reduction threshold value set comprises a plurality of noise parameter values which are arranged from small to large, the plurality of noise parameter values form a plurality of noise reduction threshold values, and the noise reduction threshold values correspond to the sound leakage compensation gears;

determining a noise reduction threshold value to which the target noise reduction belongs according to the target noise reduction and the preset noise reduction threshold value set;

and determining an acoustic leakage compensation gear corresponding to the noise reduction threshold value to which the target noise reduction belongs as a target acoustic leakage compensation gear according to the noise reduction threshold value to which the target noise reduction belongs.

5. The noise reduction control method according to claim 1, wherein the determining a target filter parameter based on the target sound leakage compensation step, and adjusting a filter parameter in a preset noise reduction filter to the target filter parameter comprises:

acquiring chip configuration information, wherein the chip configuration information is used for representing whether a filter coefficient stored in a chip supports updating;

if the filter coefficient stored in the chip supports updating, determining a target filter coefficient based on the target sound leakage compensation gear, and adjusting the filter coefficient in a preset noise reduction filter to the target filter coefficient;

and if the filter system stored in the chip does not support updating, determining a target filter gain based on the target sound leakage compensation gear, and adjusting the filter gain in a preset noise reduction filter to the target filter gain.

6. The noise reduction control method according to claim 5, wherein the filter parameters in the preset noise reduction filter include:

filter parameters in a feedforward filter; or,

filter parameters in a feedforward filter and filter parameters in a feedback filter.

7. A noise reduction control apparatus, applied to a headphone, comprising:

the system comprises a first acquisition module, a second acquisition module and a third acquisition module, wherein the first acquisition module is configured to acquire an environment time domain signal, wherein the environment time domain signal refers to a sound wave signal in the surrounding environment of the earphone represented by a time domain representation mode;

the second acquisition module is configured to acquire an ear canal time domain signal, wherein the ear canal time domain signal refers to a sound wave signal in an ear canal expressed by a time domain expression mode;

a first determining module, configured to determine a target noise reduction amount based on the environment time domain signal, the ear canal time domain signal and a preset frequency response function if the environment time domain signal and the ear canal time domain signal satisfy a preset filter parameter adjustment condition;

a second determining module, configured to determine, according to preset noise reduction configuration information and the target noise reduction amount, an acoustic leakage compensation gear corresponding to the target noise reduction amount as a target acoustic leakage compensation gear, where the noise reduction configuration information is used to represent a correspondence between a noise reduction amount threshold and an acoustic leakage compensation gear, and the noise reduction configuration information includes a plurality of noise reduction amount thresholds and an acoustic leakage compensation gear corresponding to each of the noise reduction amount thresholds;

a third determination module configured to determine a target filter parameter based on the target acoustic leakage compensation gear;

and the adjusting module is configured to adjust filter parameters in a preset noise reduction filter to the target filter parameters, wherein the noise reduction filter is used for performing noise reduction filtering processing on the input sound wave signal.

8. A noise reducing headphone comprising a housing and a feedforward microphone, a feedback microphone, a speaker and a controller disposed on the housing:

the feedforward microphone is used for collecting sound wave signals in the surrounding environment of the earphone;

the feedback microphone is used for collecting sound wave signals in the auditory canal;

the loudspeaker is used for playing sound wave signals;

the controller is communicatively coupled to the feedforward microphone, the feedback microphone, and the speaker, respectively, the controller including a processor and a memory, the memory storing computer program instructions executable by the processor, the processor configured to invoke the computer program instructions to perform the method of any of claims 1-6.

9. A non-transitory computer-readable storage medium having stored thereon computer program instructions that, when invoked by a processor, perform the method of any one of claims 1-6.

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