WO2022227982A1

WO2022227982A1 - Tws earphone and playing method and device of tws earphone

Info

Publication number: WO2022227982A1
Application number: PCT/CN2022/083464
Authority: WO
Inventors: 熊伟; 仇存收; 恽毅; 许超; 郭琴; 李岩; 田立生
Original assignee: 华为技术有限公司
Priority date: 2021-04-28
Filing date: 2022-03-28
Publication date: 2022-11-03
Also published as: CN115250397A; EP4297428A1

Abstract

The present application provides a TWS earphone and a playing method and device of the TWS earphone. The present TWS earphone comprises an audio signal processing path, a frequency divider, and at least two loudspeakers; an output end of the audio signal processing path is connected to an input end of the frequency divider; an output end of the frequency divider is connected to the at least two loudspeakers; the audio signal processing path is configured to output a loudspeaker driving signal; the frequency divider is configured to perform frequency division on the loudspeaker driving signal to obtain sub-audio signals of at least two frequency bands, the at least two frequency bands corresponding to main working frequency bands of the at least two loudspeakers; adjacent frequency bands among the at least two frequency bands partially overlap, or adjacent frequency bands among the at least two frequency bands do not overlap; and the at least two loudspeakers are configured to play the corresponding sub-audio signals. The present application can not only reflect high sound quality in frequency bands of an audio source, but also support an ultra-bandwidth voice call.

Description

TWS earphone and TWS earphone playing method and device

This application claims the priority of the Chinese patent application with the application number of 202110467311.9 and the application name "TWS earphone and TWS earphone playback method and device" filed with the Chinese Patent Office on April 28, 2021, the entire contents of which are incorporated by reference in in this application.

technical field

The present application relates to audio processing technology, and in particular, to a true wireless stereo (true wireless stereo, TWS) headset and a TWS headset playback method and device.

Background technique

In the user's headset usage scenario, the general demand is to achieve stable active noise cancellation (active noise cancellation or active noise control, ANC) or transparent transmission (hear through, HT) function while having high-quality music or broadband HD calls .

Although the current various TWS earphones implement the ANC function, they will also eliminate some music or call sounds, which will affect the sound quality and call clarity.

SUMMARY OF THE INVENTION

The present application provides a TWS earphone and a TWS earphone playing method and device, which can not only reflect high sound quality in various frequency bands of an audio source, but also support ultra-bandwidth voice calls.

In a first aspect, the present application provides a TWS earphone, comprising: an audio signal processing path, a frequency divider and at least two speakers; wherein the output end of the audio signal processing path is connected to the input end of the frequency divider; the frequency divider The output end of the frequency converter is connected to the at least two speakers; the audio signal processing path is configured to output a speaker drive signal after noise reduction or transparent transmission processing is performed on the audio source; the audio source is original music or call voice; or , the audio source includes the voice signal enhanced by the human voice and the original music or call voice; the frequency divider is configured to divide the speaker drive signal into sub-audio signals of at least two frequency bands, the at least two frequency bands The frequency bands correspond to the main working frequency bands of the at least two speakers; the adjacent frequency bands in the at least two frequency bands partially overlap, or the adjacent frequency bands in the at least two frequency bands do not overlap; the at least two speakers are configured with To play the corresponding sub audio signal.

The frequency band of the processed speaker driving signal corresponds to the frequency band of the audio source, and may include the whole frequency range of low, medium and high. However, because the main working frequency band of a single speaker may only cover part of the low, middle and high frequency bands, a single speaker cannot operate in the entire frequency band. reflect high-quality sound.

The present application controls the frequency divider to divide the frequency of the speaker drive signal in a preset manner by setting the parameters of the frequency divider. The frequency divider may be configured to divide the frequency of the speaker drive signal based on the main working frequency bands of the at least two speakers to obtain sub-audio signals of at least two frequency bands corresponding to the main working frequency bands of the at least two speakers, and then let each speaker Play the sub audio signals of the corresponding frequency bands respectively, so that the speaker maintains the best frequency response when playing the sub audio signals transmitted to it. By setting the parameters of the frequency divider to control the frequency divider to divide the frequency of the speaker driving signal according to the preset method.

At least two speakers are set in the TWS earphone of the present application, and the main working frequency bands of the at least two speakers are not identical. The frequency divider can divide the speaker drive signal into sub-audio signals of at least two frequency bands, and the adjacent frequency bands in the at least two frequency bands partially overlap or do not overlap, so that each sub-audio signal is respectively transmitted to the speakers with matching frequency bands, The aforementioned frequency band matching can mean that the main working frequency band of the speaker covers the frequency band of the sub-audio signal transmitted to it, so that the speaker maintains the best frequency response when playing the sub-audio signal transmitted to it. It reflects high sound quality and supports ultra-bandwidth voice calls.

In a possible implementation, the audio signal processing path includes: a secondary path SP filter configured to prevent the noise reduction or pass-through processing when the noise reduction or pass-through processing is concurrent with the audio source Cancellation of sound from this audio source.

In a possible implementation manner, the audio signal processing path further includes: a feedback FB microphone and a feedback filter; wherein the FB microphone is configured to pick up an ear canal signal, and the ear canal signal includes residual noise inside the ear canal signal and the music or the voice of the conversation; the SP filter is configured to input the audio source, process the audio source, and transmit the output signal and the ear canal signal to the feedback filter after superimposing; the feedback filter, is configured to generate a signal for the noise reduction or pass-through processing, the noise reduction or pass-through processed signal being one of the superimposed signals for generating the speaker drive signal.

In a possible implementation manner, the feedback FB microphone, the feedback filter and the SP filter are set in the codec CODEC.

In a possible implementation manner, the SP filter is configured to input the audio source, process the audio source, and the output signal is one of the superimposed signals of the speaker driving signal.

In a possible implementation manner, the SP filter is set in a digital signal processing DSP chip.

In the present application, the SP filter (including fixed SP filter or adaptive SP filter) is determined by the above method, which can not only realize the function of noise reduction or transparent transmission, but also prevent the transparent transmission or noise reduction technology in the process of playing music or passing through. Also remove music or call sounds.

In a possible implementation, it further includes: a first digital-to-analog converter DAC; the input end of the first DAC is connected to the output end of the audio signal processing path, and the output end of the first DAC is connected to the frequency divider The first DAC is configured to convert the speaker driving signal from a digital form to an analog form; correspondingly, the frequency divider is an analog frequency divider.

After the speaker drive signal is obtained, if the signal does not pass through the DAC, it is in digital form, but the signal played by the speaker needs to be in analog form, so the digital speaker drive signal can be converted into analog form through the first DAC The speaker driving signal in the analog form is then divided into sub audio signals of at least two frequency bands through an analog frequency divider.

This embodiment adopts the structure of first conversion and then frequency division.

In a possible implementation manner, the method further includes: at least two second DACs; the input ends of the at least two second DACs are connected to the output ends of the frequency divider, and the output ends of the at least two second DACs are connected to each other. are respectively connected with one of the at least two speakers; the second DAC is configured to convert one of the sub-audio signals of the at least two frequency bands from a digital form to an analog form; correspondingly, the frequency divider is a digital divider.

This embodiment adopts the structure of frequency division first and then conversion.

In a possible implementation manner, the main working frequency bands of the at least two speakers are not identical.

In a possible implementation manner, the at least two speakers include a moving coil speaker and a moving iron speaker.

Two speakers are set in the TWS earphone of this embodiment, namely a moving coil speaker and a moving iron speaker. The main working frequency band of the moving coil speaker is below 8.5kHz, and the main working frequency band of the moving iron speaker is above 8.5kHz. The frequency divider divides the analog speaker drive signal into a sub audio signal below 8.5kHz and a sub audio signal above 8.5kHz. The moving coil speaker can maintain the best frequency response by playing the sub audio signal below 8.5kHz. The sub-audio signal above 8.5kHz can maintain the best frequency response, so that the TWS headset can not only reflect the high sound quality in each frequency band of the audio source, but also support ultra-bandwidth voice calls.

In a possible implementation manner, the at least two speakers include a moving coil speaker, a moving iron speaker, a MEMS speaker and a planar vibration diaphragm.

Four speakers are set in the TWS earphone of this embodiment, namely, a moving coil speaker, a moving iron speaker, a MEMS speaker and a plane vibration diaphragm. Above 8.5kHz, the main working frequency band of MEMS speakers depends on the application form. The main working frequency band of in-ear headphones is the full frequency band, the main working frequency band of headphone is weaker below 7kHz, and the main working frequency band is high frequency above 7kHz. The main working frequency band of the flat vibrating diaphragm is 10kHz~20kHz, in this way, the frequency divider can be set to divide the analog speaker driving signal into four sub-frequency bands, and the sub-audio signal below 8.5kHz can be played by the moving coil speaker to maintain the best frequency response. , the moving iron speaker can maintain the best frequency response when playing sub-audio signals above 8.5kHz, the MEMS speaker can maintain the best frequency response when playing sub-audio signals above 7kHz, and the flat vibrating diaphragm can maintain the best frequency response when playing sub-audio signals above 10kHz frequency response, so that the TWS headset can not only reflect high sound quality in various frequency bands of the audio source, but also support ultra-bandwidth voice calls.

In a second aspect, the present application provides a method for playing a TWS headset, which is applied to the TWS headset according to any one of the first aspects above; the method includes: acquiring an audio source, where the audio source is original music or call voice, or, the audio source includes a voice signal enhanced by human voice and the original music or call voice; noise reduction or transparent transmission processing is performed on the audio source to obtain a speaker drive signal; The driving signal is divided into sub-audio signals of at least two frequency bands, and the adjacent frequency bands in the at least two frequency bands partially overlap, or the adjacent frequency bands in the at least two frequency bands do not overlap; Playing one of the sub audio signals of the at least two frequency bands.

In a possible implementation manner, performing noise reduction or transparent transmission processing on the audio source to obtain the speaker drive signal includes: obtaining a fixed secondary path SP filter through a codec CODEC; filtering according to the fixed SP The device processes the audio source to obtain a filtered signal; performs noise reduction or transparent transmission processing on the filtered signal to obtain the speaker drive signal.

In a possible implementation manner, the obtaining the fixed secondary path SP filter through the codec CODEC includes: obtaining an estimated SP filter according to a preset speaker drive signal and the ear canal signal picked up by the feedback FB microphone , the ear canal signal includes the residual noise signal inside the ear canal; when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within the set range, the estimated SP filter Determined as the fixed SP filter.

In a possible implementation manner, after obtaining the estimated SP filter according to the preset speaker drive signal and the ear canal signal picked up by the feedback FB microphone, the method further includes: when the signal obtained by the estimated SP filter When the difference signal with the ear canal signal is within the set range, the parameters of the cascaded second-order filter are obtained according to the target frequency response of the estimated SP filter and the preset frequency division requirements; The parameters of the second-order filter are obtained from the SP cascaded second-order filter, and the SP cascaded second-order filter is used as the fixed SP filter.

In a possible implementation manner, performing noise reduction or transparent transmission processing on the audio source to obtain the speaker drive signal includes: obtaining an adaptive SP filter through a digital signal processing DSP chip; filtering according to the adaptive SP The device processes the audio source to obtain a filtered signal; performs noise reduction or transparent transmission processing on the filtered signal to obtain the speaker drive signal.

In a possible implementation manner, obtaining the adaptive SP filter through a digital signal processing DSP chip includes: obtaining a real-time noise signal; obtaining an estimated SP filter according to the audio source and the real-time noise signal; When the difference signal between the signal obtained by the estimated SP filter and the real-time noise signal is within a set range, the estimated SP filter is determined as the adaptive SP filter.

In a possible implementation manner, the acquiring a real-time noise signal includes: acquiring an external signal picked up by a feed-forward FF microphone and an ear canal signal picked up by a feedback FB microphone, where the external signal includes an external noise signal and the music Or call voice, the ear canal signal includes the residual noise signal inside the ear canal and the music or the call voice; obtain the voice signal picked up by the main microphone; subtract the external signal and the ear canal from the voice signal The signal obtains the real-time noise signal.

In a possible implementation manner, the at least two speakers include a moving coil speaker, a moving iron speaker, a microelectromechanical system MEMS speaker, and a planar vibrating diaphragm.

In a third aspect, the present application provides a playback device for a TWS headset, which is applied to the TWS headset in the first aspect; the device includes: an acquisition module for acquiring an audio source, where the audio source is original music or call voice, or the audio source includes the voice signal enhanced by human voice and the original music or call voice; the processing module is used to perform noise reduction or transparent transmission processing on the audio source to obtain a speaker drive signal; A frequency dividing module, configured to divide the speaker drive signal into sub-audio signals of at least two frequency bands, and adjacent frequency bands in the at least two frequency bands partially overlap, or, adjacent frequency bands in the at least two frequency bands The frequency bands do not overlap; a playing module is configured to play one of the sub audio signals of the at least two frequency bands through at least two speakers respectively.

In a possible implementation manner, the processing module is specifically configured to obtain a fixed secondary path SP filter through a codec CODEC; process the audio source according to the fixed SP filter to obtain a filtered signal; The filtered signal is subjected to noise reduction or transparent transmission processing to obtain the speaker driving signal.

In a possible implementation manner, the processing module is specifically configured to obtain an estimated SP filter according to a preset speaker drive signal and an ear canal signal picked up by the feedback FB microphone, and the ear canal signal includes an internal ear canal signal. The residual noise signal and the music or talking speech; when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within the set range, the estimated SP filter is determined as the The fixed SP filter described above.

In a possible implementation manner, the processing module is further configured to, when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within a set range, according to the estimated SP The target frequency response of the filter and the preset frequency division requirements obtain the parameters of the cascaded second-order filter; according to the parameters of the cascaded second-order filter, the SP cascaded second-order filter is obtained, and the SP cascaded two order filter as the fixed SP filter.

In a possible implementation manner, the processing module is specifically configured to obtain an adaptive SP filter through a digital signal processing DSP chip; process the audio source according to the adaptive SP filter to obtain a filtered signal; The filtered signal is subjected to noise reduction or transparent transmission processing to obtain the speaker driving signal.

In a possible implementation manner, the processing module is specifically configured to obtain a real-time noise signal; obtain an estimated SP filter according to the audio source and the real-time noise signal; when the signal obtained through the estimated SP filter When the difference signal with the real-time noise signal is within a set range, the estimated SP filter is determined as the adaptive SP filter.

In a possible implementation manner, the processing module is specifically configured to acquire an external signal picked up by a feedforward FF microphone and an ear canal signal picked up by a feedback FB microphone, where the external signal includes an external noise signal and the music or Call voice, the ear canal signal includes the residual noise signal inside the ear canal and the music or the call voice; obtain the voice signal picked up by the main microphone; subtract the external signal and the ear canal signal from the voice signal Obtain a signal difference; obtain the estimated SP filter according to the audio source and the signal difference.

In a fourth aspect, the present application provides a computer-readable storage medium, comprising a computer program, which, when executed on a computer, causes the computer to execute the method of any one of the above-mentioned second aspects.

In a fifth aspect, the present application provides a computer program, when the computer program is executed by a computer, for performing the method of any one of the above-mentioned second aspects.

Description of drawings

FIG. 1 is an exemplary structural schematic diagram of a related art TWS headset;

FIG. 2a is an exemplary structural schematic diagram of a related art TWS headset;

FIG. 2b is an exemplary structural schematic diagram of a related art TWS headset;

3 is a schematic structural diagram of an exemplary TWS headset of the present application;

4 is a schematic structural diagram of an exemplary TWS headset of the present application;

Fig. 5a is an exemplary acquisition flow chart of the fixed SP filter of the present application

Fig. 5b is an exemplary acquisition flow chart of the fixed SP filter of the present application

FIG. 6 is a schematic structural diagram of an exemplary TWS headset of the present application

FIG. 7a is an exemplary schematic diagram of the signal frequency division of the present application;

FIG. 7b is an exemplary schematic diagram of signal frequency division of the present application;

FIG. 7c is an exemplary schematic diagram of signal frequency division of the present application;

FIG. 7d is an exemplary schematic diagram of signal frequency division of the present application;

FIG. 8a is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 8b is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 8c is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 8d is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 8e is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 9a is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 9b is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 9c is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 9d is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 9e is an exemplary structural schematic diagram of the TWS headset of the present application;

FIG. 10 is an exemplary flowchart of the playback method of the TWS headset of the present application;

FIG. 11 is an exemplary structural diagram of the playback device of the TWS earphone of the present application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the accompanying drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application. , not all examples. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

The terms "first", "second", etc. in the description, embodiments and claims of the present application and the drawings are only used for the purpose of distinguishing and describing, and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implied order. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, eg, comprising a series of steps or elements. A method, system, product or device is not necessarily limited to those steps or units expressly listed, but may include other steps or units not expressly listed or inherent to the process, method, product or device.

It should be understood that, in this application, "at least one (item)" refers to one or more, and "a plurality" refers to two or more. "And/or" is used to describe the relationship between related objects, indicating that there can be three kinds of relationships, for example, "A and/or B" can mean: only A, only B, and both A and B exist , where A and B can be singular or plural. The character "/" generally indicates that the associated objects are an "or" relationship. "At least one item(s) below" or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (a) of a, b or c, can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c" ", where a, b, c can be single or multiple.

FIG. 1 is a schematic diagram of an exemplary structure of a related art TWS headset. As shown in FIG. 1 , the TWS headset includes three types of microphones, namely a main microphone, a feedforward (FF) microphone and a feedback (FB) microphone, wherein the main microphone is used to pick up the human voice in the call, and the FF microphone It is used to pick up the external noise signal, and the FB microphone is used to pick up the residual noise signal inside the ear canal; the TWS headset also includes a moving coil speaker, which is used to play the processed music or call voice.

Based on the structure shown in FIG. 1 , FIG. 2 a is a schematic structural diagram of an exemplary TWS headset in the related art. As shown in Figure 2a, the main microphone and the FF microphone are respectively connected to the input end of the vocal enhancement filter, and the output end of the vocal enhancement filter and the audio source (including music and call voice) are superimposed by the stacker 1 to obtain a downlink link signal; the downlink signal is transmitted to one input of the stacker 2; the downlink signal is also transmitted to the input of the secondary path (SP) filter; the input of the FF microphone and the feedforward filter The output end of the feedforward filter is connected to the other input end of the stacker 2; the FB microphone is connected to one input end of the stacker 3, the output end of the SP filter is connected to the other input end of the stacker 3, The output end of the stacker 3 is connected to the input end of the feedback filter, and the output end of the feedback filter is connected to the third input end of the stacker 2; the output end of the stacker 2 is connected to the digital to analog converter (digital to analog converter, The input end of the DAC) is connected, and the output end of the DAC is connected to the moving coil speaker.

Active Noise Cancellation & Transparent Transmission & Enhanced Hearing (ANC&HT&AH, AHA) joint controllers are respectively connected with vocal enhancement filter, feedforward filter, feedback filter and SP filter. The role of the AHA joint controller: In order to ensure the normal and stable operation of the TWS headset, some abnormal situations need to be handled by the TWS headset itself, so an AHA joint controller is required. The AHA joint controller analyzes multiple signals to determine the current state of ANC, HT or augmented hearing (AH), and then determines whether abnormal conditions such as whistling and clipping occur, so as to implement corresponding processing. The aforementioned filter parameter values are used to realize the control of the system.

In the above structure, the vocal enhancement filter, the audio source and the AHA joint controller are arranged in the digital signal processing (digital signal process, DSP) chip, and the feedforward filter, the feedback filter, the SP filter and the DAC are arranged in the codec. in the encoder (coder-decoder, CODEC).

Based on the structure shown in FIG. 1 , FIG. 2 b is a schematic structural diagram of an exemplary TWS headset of the related art. As shown in Figure 2b, the difference from the structure shown in Figure 2a is that the vocal enhancement filter is moved from the DSP chip to the CODEC.

Based on the structures shown in Figures 1 to 2b, the TWS headset can implement the following functions:

Active noise reduction: The FF microphone picks up the external noise signal and generates the feedforward noise reduction signal through the feedforward filter; the FB microphone picks up the residual noise signal inside the ear canal, and generates the feedback noise reduction signal through the feedback filter. The feedforward noise reduction signal, the feedback noise reduction signal and the downlink signal are superimposed to form the final speaker drive signal, and the analog speaker drive signal is generated after digital-to-analog conversion by the DAC. When the analog loudspeaker driving signal is played in a reverse manner in the moving coil loudspeaker, the analog audio signal can be obtained by canceling the audio signal in the space. In this way, low-frequency noise within a certain frequency band can be eliminated, thereby achieving the purpose of noise reduction.

Transparent transmission: The FF microphone picks up the external noise signal and generates the feedforward compensation signal through the feedforward filter; the FB microphone picks up the acoustic signal inside the ear canal and generates the feedback suppression signal through the feedback filter. The feedforward compensation signal, the feedback suppression signal and the downlink signal are superimposed to form the final speaker drive signal, and the analog speaker drive signal is generated after digital-to-analog conversion by the DAC. The analog speaker driving signal is played in the moving coil speaker, which can weaken or suppress low-frequency noise and compensate high-frequency signals, so as to obtain an analog audio signal that realizes acoustic compensation. In this way, the "occlusion" effect of active voice listening (the wearer's own voice heard by himself) or the "stethoscope" effect of body part vibration (such as walking, chewing, scratching your head, etc. with headphones) is weakened or suppressed, passive The high-frequency sound within a certain frequency band of listening sounds (such as human voice or music in the environment) is compensated, so as to achieve the purpose of transparent transmission.

It should be noted that in the above step of superimposing to obtain the final speaker driving signal, the superimposed signal may include the feedforward compensation signal, the feedback suppression signal and the downlink signal, or may include the feedforward compensation signal and the feedback suppression signal. and either or both of the downlink signal. For example, when noise reduction is performed while the user is listening to music, the superimposed signal may include the aforementioned three; when the user just wants to perform noise reduction through headphones so as to be in a quiet environment, the superimposed signal may include the feed compensation signal and feedback suppression signals, excluding downlink signals.

Vocal enhancement and music/call concurrency: When the vocal enhancement function is implemented on the DSP side, the FF microphone and main microphone signals are sent to the vocal enhancement filter for processing to obtain a signal in which ambient noise is suppressed and the human voice is preserved. Then the signal is down-streamed to the CODEC, superimposed with the signals output by the feedforward filter and the feedback filter respectively to obtain the speaker drive signal, and after digital-to-analog conversion by the DAC, the analog speaker drive signal is output for the moving coil speaker to play. Since the sound played by the moving coil speaker will be picked up by the FB microphone, in order to prevent the played sound from being denoised by the feedback filter, the estimated signal played by the moving coil speaker can be subtracted from the signal picked up by the FB microphone, In this way, this part of the signal will not be noise-reduced by the feedback filter, thus realizing the concurrency of vocal enhancement and music/calling, and the ANC/HT function can also be realized on this basis.

In Figure 2a, the realization of vocal enhancement in DSP is a guarantee of computational power overhead. The noise reduction effect and the playback effect after processing are stable, but the delay is long, and it sounds like a reverberation. In Figure 2b, the human voice enhancement is implemented in the CODEC. The algorithm is relatively fixed and simple, the time delay is short, and the reverberation sense is low, but the noise reduction effect is limited.

The structure of the TWS earphone shown in Figure 1 to Figure 2b, for high-frequency music, especially for music signals in the frequency band above 8.5kHz, the playback sound quality may be seriously damaged, affecting the playback effect of music; for high-frequency speech, especially for 8.5kHz Voice signals in the above frequency bands are not supported, resulting in limited bandwidth for voice calls.

The present application provides a speaker structure of a TWS earphone, which can improve the above technical problems.

FIG. 3 is a schematic structural diagram of an exemplary TWS headset of the present application. As shown in FIG. 3 , the TWS headset 30 includes three types of microphones, namely the main microphone 31 , the FF microphone 32 and the FB microphone 33 , wherein the main microphone 31 is used to pick up the human voice during the call, and the FF microphone 32 is used to pick up the external noise signal , the FB microphone 33 is used to pick up the residual noise signal inside the ear canal.

The TWS earphone 30 also includes a moving coil speaker 34a and a moving iron speaker 34b. The main working frequency band of the moving coil speaker 34a is less than 8.5kHz, and the main working frequency band of the moving iron speaker 34b is greater than 8.5kHz. It should be noted that this application does not specifically limit the number of speakers, as long as there are at least two speakers, and the at least two speakers may have different main working frequency bands of each speaker, or may also have the main operating frequency bands of some speakers. The working frequency band is the same, and the main working frequency band of another part of the speakers is different from the main working frequency band of the aforementioned part of the speakers. For example, for three speakers (1-3), the main working frequency band of speaker 1 is the same as that of speaker 2, and the main working frequency band of speaker 3 is different from that of speaker 1 and speaker 2. For another example, among the three speakers (1-3), the main working frequency bands of the speaker 1, the speaker 2 and the speaker 3 are all different. Optionally, the at least two speakers may also include a moving coil speaker, a moving iron speaker, a micro-electro-mechanical systems (MEMS) MEMS speaker and a planar vibrating diaphragm, wherein the main working frequency band of the moving coil speaker is Less than 8.5kHz, the main working frequency band of the moving iron speaker is greater than 8.5kHz, the main working frequency band of the MEMS speaker depends on the application form, the main working frequency band of the in-ear headphone is the full frequency band, and the main working frequency band of the headphone is below 7kHz. Weak, the main working frequency band is high frequency above 7kHz, and the main working frequency band of the plane vibrating diaphragm is 10kHz~20kHz.

Based on the TWS headset shown in FIG. 3 , FIG. 4 is a schematic structural diagram of an exemplary TWS headset of the present application. As shown in FIG. 4 , the TWS earphone 40 includes: an audio signal processing path 41, a frequency divider 42 and at least two speakers 43; wherein, the output end of the audio signal processing path 41 is connected to the input end of the frequency divider 42; frequency division The output end of the speaker 42 is connected to at least two speakers 43 .

The audio signal processing path 41 is configured to output a speaker drive signal after performing noise reduction or transparent transmission processing on the audio source; the audio source is the original music or call voice; music or call voice.

The frequency divider 42 is configured to divide the speaker drive signal into sub-audio signals of at least two frequency bands, the at least two frequency bands correspond to the main working frequency bands of the at least two speakers 43; the adjacent frequency band parts in the at least two frequency bands Overlapping, or at least two adjacent bands in the two bands do not overlap. At least two speakers 43 are configured to play corresponding sub audio signals.

The frequency divider 42 of the present application may be configured to divide the frequency of the speaker drive signal based on the main operating frequency bands of the at least two speakers, to obtain sub-audio signals of at least two frequency bands corresponding to the main operating frequency bands of the at least two speakers, respectively, Then let each speaker play the sub audio signal of the corresponding frequency band, so that the speaker maintains the best frequency response when playing the sub audio signal transmitted to it. The frequency divider 42 can be controlled to divide the frequency of the speaker driving signal in a preset manner by setting the parameters of the frequency divider 42 .

In a possible implementation manner, the above-mentioned audio signal processing path 41 may adopt the structure shown in FIG. 2 a or FIG. 2 b . At this time, the SP filter is set in the codec (coder-decoder, CODEC), and the fixed value is obtained through the CODEC. SP filter.

The CODEC can obtain the estimated SP filter according to the preset speaker drive signal and the ear canal signal picked up by the FB microphone. The ear canal signal includes the residual noise signal inside the ear canal; when the signal obtained by the estimated SP filter and the ear canal signal When the difference signal of is within the set range, the estimated SP filter is determined as a fixed SP filter.

Fig. 5a is an exemplary acquisition flow chart of the fixed SP filter of the present application. As shown in Fig. 5a, a speaker driving signal x[n] is preset, and after passing through the frequency divider, at least two speakers are pushed to emit sound. The sound is transmitted to the FB microphone, picked up by the FB microphone, and converted into a digital signal y[n].

Usually, the transfer function of the SP filter can be assumed to be a high-order FIR filter, which can be iteratively modeled by the least mean square error (LMS) algorithm. The transfer function S(z) of the real SP filter is unknown, but its All the information is contained in the speaker drive signal x[n] and the digital signal y[n] picked up by the FB microphone, so it can be passed through a higher order FIR filter

Model S(z) as an estimated SP filter. input x[n]

get

for y[n] and

Calculate the difference to get the error signal e[n]. When e[n] is within the set range, it is considered that the algorithm has converged to a satisfactory state, and it can be considered that the high-order FIR filter at this time

It is approximately equal to the true S(z), which can be determined to be the transfer function of the fixed SP filter. The above process can be iteratively modeled using a least mean square (Least mean square, LMS).

Further, in addition to using a finite-length unit impulse response (FIR) filter to simulate a fixed SP filter, the infinite impulse response (IIR) filter on the CODEC side can also be used to simulate a fixed SP filter. filter. Fig. 5b is an exemplary acquisition flow chart of the fixed SP filter of the present application. As shown in Fig. 5b, when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within the set range, according to the estimation The parameters of the cascaded second-order filter are obtained from the target frequency response of the SP filter and the preset frequency division requirements; the SP cascaded second-order filter is obtained according to the parameters of the cascaded second-order filter, and the SP cascaded second-order filter is as a fixed SP filter.

(1) CODEC is based on the FIR filter that has been obtained

Calculate the target frequency response.

s=[s ₀ s ₁ …s _N-1 ], N represents the filter order, and k represents the frequency point number. The corresponding target response is calculated using formula (1):

(2) Perform frequency division processing on the target frequency response, and set different weight coefficients ω[k] in different frequency bands.

(3) The IIR filter parameters are obtained from the conversion process of the FIR filter to the IIR filter, and the process requires the target responses of the two to be as consistent as possible.

From a mathematical point of view, it is required to optimize the objective function of formula (2) to obtain the coefficients of multiple IIR filters:

Among them, B[k] and A[k] are the complex frequency responses of the IIR filter coefficients b and a respectively, and the calculation method is the same as that of formula (1).

(4) IIR filter implementation

Using the optimization algorithm, a set of IIR filter parameters under the minimum mean square can be found, and the IIR filter obtained from this set of IIR filter parameters can be used as the final fixed SP filter and put into the CODEC for hardening implementation.

In a possible implementation manner, the above-mentioned audio signal processing path 41 may adopt the structure shown in FIG. 6 . At this time, the SP filter is set in a digital signal processing (digital signal process, DSP) chip, and the adaptive filter is obtained through the DSP chip. SP filter.

The DSP chip can obtain the real-time noise signal, and obtain the estimated SP according to the audio source (the audio source is the original music or voice of the call; or, the audio source includes the voice signal that has been enhanced by the human voice and the original music or voice of the call) and the real-time noise signal. The filter determines the estimated SP filter as an adaptive SP filter when the difference signal between the signal obtained by the estimated SP filter and the real-time noise signal is within the set range.

The above-mentioned acquisition of the real-time noise signal may be to acquire the external signal picked up by the FF microphone (the external signal includes the external noise signal and music or voice of a call) and the ear canal signal picked up by the FB microphone (the ear canal signal includes the residual noise signal inside the ear canal and music. Or call voice), and then obtain the voice signal picked up by the main microphone, and subtract the external signal and the ear canal signal from the voice signal to obtain a real-time noise signal.

The difference between this embodiment and the above-mentioned embodiment for obtaining a fixed SP filter is that: x[n] represents an audio source, and y[n] represents a real-time noise signal, that is, x[n]=dnlink[n], y[n] =fb[n]-ff[n]*A(z)-fb[n-1]*C(z), fb[n] represents the voice signal picked up by the main microphone, ff[n]*A(z) It represents the external signal picked up by the FF microphone, and fb[n-1]*C(z) represents the ear canal signal picked up by the FB microphone. In this embodiment, the process shown in FIG. 5a can also be used to obtain a high-order FIR filter corresponding to the minimum error signal e[n]

Since the audio source is real-time, the noise reduction or transparent transmission function of the TWS headset will be concurrent with the music or the voice of the call. At this time, the signal picked up by the FB microphone cannot be directly estimated by the SP filter, and it is necessary to remove the influence of other signals. Modeling analysis is to obtain real-time noise signal, so the SP filter obtained at this time can be adapted to the real-time situation of the audio source and noise signal instead of being fixed.

Exemplarily, it is assumed that the TWS earphone includes two speakers: a moving coil speaker and a moving iron speaker. The dotted line represents the frequency response curve of the moving coil speaker, the single-dotted line represents the frequency response curve of the moving iron speaker, and the solid line represents the crossover line.

FIG. 7a is an exemplary schematic diagram of signal frequency division of the present application. As shown in FIG. 7a, the frequency divider 42 is configured to attenuate the dynamic speaker in the non-main operating frequency band, and keep the dynamic speaker in the main operating frequency band. The power of the moving iron speaker is attenuated in the non-main working frequency band of the moving iron speaker, the power of the moving iron speaker in the main working frequency band is retained, and the frequency is divided at the intersection frequency of the attenuation frequency band of the moving coil speaker and the moving iron speaker. Get the sub audio signal of the two frequency bands.

FIG. 7b is an exemplary schematic diagram of signal frequency division of the application. As shown in FIG. 7b, the frequency divider 42 is configured to align and attenuate in the non-main working frequency band of the moving iron speaker, and retain the moving iron speaker in the main working frequency band. power, and divide the frequency at a certain frequency point in the attenuation frequency band of the moving iron speaker to obtain sub-audio signals of two frequency bands.

Fig. 7c is an exemplary schematic diagram of the frequency division of the signal of the present application. As shown in Fig. 7c, the frequency divider 42 is configured to perform two-stage attenuation in the non-main operating frequency band of the moving coil speaker, leaving the moving coil speaker at The power of the main working frequency band is attenuated in two stages in the non-main working frequency band of the moving iron speaker, retaining the power of the moving iron speaker in the main working frequency band, and attenuating the first and second attenuation bands of the moving iron speaker A frequency division is performed at the transition frequency point of the frequency band, and a frequency division is performed at the transition frequency point of the first attenuation frequency band and the second attenuation frequency band of the moving coil speaker to obtain sub audio signals of three frequency bands.

Exemplarily, it is assumed that the TWS earphone includes three speakers: a moving coil speaker, a moving iron speaker, and a MEMS speaker. The dotted line represents the frequency response curve of the moving coil speaker, the single-dotted line represents the frequency response curve of the moving iron speaker, the double-dotted line represents the frequency response curve of the MEMS speaker, and the solid line represents the crossover line.

Fig. 7d is an exemplary schematic diagram of the frequency division of the signal of the present application. As shown in Fig. 7d, on the basis of the example shown in Fig. 7c, the frequency divider 42 is configured to attenuate the MEMS speaker in the non-main operating frequency band , retain the power of the MEMS speaker in the main working frequency band, and perform a frequency division at the intersection frequency point in the respective attenuation frequency bands of the moving iron speaker and the MEMS speaker, and obtain a total of four frequency bands of sub-audio signals.

It should be noted that the examples shown in FIGS. 7 a to 7 d are several examples in which the frequency divider 42 divides the speaker driving signal, and the present application does not limit the specific frequency division method of the frequency divider 42 .

In a possible implementation manner, FIG. 8a is a schematic structural diagram of an exemplary TWS headset of the present application. As shown in FIG. 8a , on the basis of the structure shown in FIG. 4 , the TWS earphone 40 further includes: a first DAC 44 . The input end of the first DAC 44 is connected with the output end of the audio signal processing path 41, and the output end of the first DAC 44 is connected with the input end of the frequency divider 42.

The first DAC 44 is configured to convert the speaker drive signal from digital to analog. Correspondingly, the frequency divider 42 is an analog frequency divider.

In the structure shown in Figure 2a or Figure 2b, after the speaker driving signal is obtained, if the signal does not pass through the DAC, it is in digital form, but the signal played by the speaker needs to be in analog form, so it can pass the first DAC first. The speaker driving signal in digital form is converted into a speaker driving signal in analog form, and then the analog frequency divider is used to divide the frequency of the speaker driving signal in analog form into sub audio signals of at least two frequency bands.

This embodiment adopts a structure of converting first and then dividing the frequency.

Exemplarily, FIG. 8b is an exemplary structural schematic diagram of the TWS headset of the present application. As shown in Fig. 8b, the structure of this embodiment is a more detailed implementation of the structure shown in Fig. 8a.

The main microphone 601 and the FF microphone 602 in the TWS earphone 60 are respectively connected to the input end of the vocal enhancement filter 603 , and the output end of the vocal enhancement filter 603 and the audio source 604 (including music and call speech) The downlink signal is obtained after superposition; the downlink signal is transmitted to an input of the stacker 2; the downlink signal is also transmitted to the input of the SP filter 605; connected, the output end of the feedforward filter 606 is connected to the other input end of the stacker 2; the FB microphone 607 is connected to one input end of the stacker 3, and the output end of the SP filter 605 is connected to the other input end of the stacker 3 connected, the output end of the stacker 3 is connected to the input end of the feedback filter 608, and the output end of the feedback filter 608 is connected to the third input end of the stacker 2; the output end of the stacker 2 is connected to the digital-to-analog converter (DAC) ) 609 is connected to the input end, the output end of the DAC 609 is connected to the input end of the analog frequency divider 610, and the output end of the analog frequency divider 610 is connected to the moving coil speaker 611a and the moving iron speaker 611b. The AHA joint controller 612 is connected to the vocal enhancement filter 603, the feedforward filter 606, the feedback filter 608 and the SP filter 605, respectively.

The TWS earphone 60 in this embodiment is provided with two speakers, namely a moving coil speaker 611a and a moving iron speaker 611b. The main working frequency band of the moving coil speaker 611a is below 8.5 kHz, and the main working frequency band of the moving iron speaker 611b is above 8.5 kHz. , so that the frequency divider 42 can be set to divide the analog speaker drive signal into a sub audio signal below 8.5kHz and a sub audio signal above 8.5kHz, and the moving coil speaker 611a can maintain the optimal playback of the sub audio signal below 8.5kHz Frequency response, the moving iron speaker 611b can maintain the best frequency response by playing sub-audio signals above 8.5kHz, so that the TWS earphone 60 can not only reflect high sound quality in various frequency bands of the audio source, but also support ultra-bandwidth voice calls.

Exemplarily, FIG. 8c is an exemplary schematic structural diagram of the TWS headset of the present application. As shown in FIG. 8c, the structure of this embodiment is another more detailed implementation of the structure shown in FIG. 8a.

The difference from the structure shown in FIG. 8b is that the output end of the analog frequency divider 610 is connected to the moving coil speaker 611a, the moving iron speaker 611b, the MEMS speaker 611c and the planar vibrating diaphragm 611d.

The TWS earphone 60 in this embodiment is provided with four speakers, namely a moving coil speaker 611a, a moving iron speaker 611b, a MEMS speaker 611c, and a plane vibration diaphragm 611d. The main working frequency of the moving coil speaker 611a is below 8.5 kHz, and the moving iron The main working frequency band of the speaker 611b is above 8.5kHz, and the main working frequency band of the MEMS speaker 611c depends on the application form. For high frequencies above 7 kHz, the main working frequency band of the planar vibrating diaphragm 611d is 10 kHz to 20 kHz. In this way, the frequency divider 42 can be set to divide the analog speaker driving signal into four sub-frequency bands, and the moving coil speaker 611a plays 8.5 kHz. The following sub-audio signals can maintain the best frequency response, the moving iron speaker 611b can maintain the best frequency response by playing the sub-audio signal above 8.5kHz, and the MEMS speaker 611c can maintain the best frequency response by playing the sub-audio signal above 7kHz, and the plane vibrates The diaphragm 611d can maintain the best frequency response by playing the sub-audio signal above 10 kHz, so that the TWS earphone 60 can not only reflect the high sound quality in each frequency band of the audio source, but also support ultra-bandwidth voice calls.

In the above structure, the vocal enhancement filter 603, the audio source 604 and the AHA joint controller 612 are arranged in a digital signal processing (digital signal process, DSP) chip, the feedforward filter 606, the feedback filter 608, and the SP filter 605. And the DAC 609 is set in the codec (coder-decoder, CODEC).

Exemplarily, FIG. 8d is an exemplary schematic structural diagram of the TWS headset of the present application. As shown in Fig. 8d, the structure of this embodiment is a more detailed implementation of the structure shown in Fig. 8a.

The difference from the structure shown in Fig. 8b is that the vocal enhancement filter 603 is moved from the DSP chip to the CODEC.

Exemplarily, FIG. 8e is a schematic structural diagram of an exemplary TWS headset of the present application. As shown in FIG. 8e, the structure of this embodiment is a more detailed implementation of the structure shown in FIG. 8a.

The difference from the structure shown in Fig. 8c is that the vocal enhancement filter 603 is moved from the DSP chip to the CODEC.

In a possible implementation manner, FIG. 9a is a schematic structural diagram of an exemplary TWS headset of the present application. As shown in FIG. 9a , on the basis of the structure shown in FIG. 4 , the TWS earphone 40 further includes: at least two second DACs 45 . The input ends of the at least two second DACs 45 are connected to the output ends of the frequency divider 42, and the output ends of the at least two second DACs 45 are respectively connected to one of the at least two speakers 43.

The second DAC 45 is configured to convert one of the sub-audio signals of at least two frequency bands from a digital form to an analog form. Correspondingly, the frequency divider 42 is a digital frequency divider.

In the structure shown in Figure 2a or Figure 2b, after the speaker driving signal is obtained, if the signal does not pass through the DAC, it is in digital form, but the signal played by the speaker needs to be in analog form, so it can be divided by digital frequency first. The device divides the speaker driving signal in digital form into sub audio signals in at least two frequency bands, and then converts the sub audio signals in digital form transmitted to it into sub audio in analog form through at least two second DACs respectively. Signal.

Exemplarily, FIG. 9b is an exemplary schematic structural diagram of the TWS headset of the present application. As shown in FIG. 9b, the structure of this embodiment is a more detailed implementation of the structure shown in FIG. 9a.

The main microphone 701 and the FF microphone 702 in the TWS earphone 70 are respectively connected to the input end of the vocal enhancement filter 703 , and the output end of the vocal enhancement filter 703 and the audio source 704 (including music and talking voice) are connected to the The downlink signal is obtained after superposition; the downlink signal is transmitted to one input of the stacker 2; the downlink signal is also transmitted to the input of the SP filter 705; connected, the output end of the feedforward filter 706 is connected to the other input end of the stacker 2; the FB microphone 707 is connected to one input end of the stacker 3, and the output end of the SP filter 705 is connected to the other input end of the stacker 3 connected, the output end of the superimposed device 3 is connected to the input end of the feedback filter 708, and the output end of the feedback filter 708 is connected to the third input end of the superimposed device 2; The input end is connected, and the output end of the digital frequency divider 709 is connected to the input ends of the two DACs 710a and 710b; the output end of the DAC 710a is connected to the moving speaker 711a, and the output end of the DAC 710b is connected to the moving iron speaker 711b. The AHA joint controller 712 is respectively connected to the vocal enhancement filter 703 , the feedforward filter 706 , the feedback filter 708 and the SP filter 705 .

Exemplarily, FIG. 9c is an exemplary schematic structural diagram of the TWS headset of the present application. As shown in Fig. 9c, the structure of this embodiment is a more detailed implementation of the structure shown in Fig. 9a.

The TWS earphone 70 in this embodiment is provided with four speakers, namely a moving coil speaker 711a, a moving iron speaker 711b, a MEMS speaker 711c, and a plane vibration diaphragm 711d. The main working frequency of the moving coil speaker 711a is below 8.5 kHz, and the moving iron The main working frequency band of the speaker 711b is above 8.5kHz, and the main working frequency band of the MEMS speaker 711c depends on the application form. For high frequencies above 7 kHz, the main working frequency band of the planar vibrating diaphragm 711d is 10 kHz to 20 kHz. In this way, the frequency divider 42 can be set to divide the analog speaker driving signal into four sub-frequency bands, and the moving coil speaker 711a plays 8.5 kHz. The following sub-audio signals can maintain the best frequency response, the moving iron speaker 711b can maintain the best frequency response by playing the sub-audio signal above 8.5kHz, and the MEMS speaker 711c can maintain the best frequency response by playing the sub-audio signal above 7kHz, and the plane vibrates The diaphragm 711d can maintain the best frequency response by playing sub-audio signals above 10 kHz, so that the TWS earphone 70 can not only reflect high sound quality in various frequency bands of the audio source, but also support ultra-bandwidth voice calls.

In the above structure, the vocal enhancement filter 703, the audio source 704 and the AHA joint controller 712 are arranged in the DSP chip, and the feedforward filter 706, the feedback filter 708, the SP filter 705 and the DAC 709 are arranged in the CODEC.

Exemplarily, FIG. 9d is an exemplary schematic structural diagram of the TWS headset of the present application. As shown in FIG. 9d, the structure of this embodiment is a more detailed implementation of the structure shown in FIG. 9a.

The difference from the structure shown in Fig. 9b is that the vocal enhancement filter 703 is moved from the DSP chip to the CODEC.

Exemplarily, FIG. 9e is an exemplary schematic structural diagram of the TWS headset of the present application. As shown in FIG. 9e, the structure of this embodiment is a more detailed implementation of the structure shown in FIG. 9a.

The difference from the structure shown in Fig. 9c is that the vocal enhancement filter 703 is moved from the DSP chip to the CODEC.

FIG. 10 is an exemplary flowchart of a method for playing a TWS headset of the present application. As shown in FIG. 10 , the method of this embodiment may be applied to the TWS headset in the above-mentioned embodiments. The method can include:

Step 1001: Acquire an audio source.

Optionally, the audio source is original music or call voice, that is, the audio source may be music, video sound, etc. that the user is listening to with the headset, or the call voice when the user is making a call with the headset. The audio source may come from the player of the electronic device. Optionally, the audio source includes the voice signal enhanced by the human voice and the original music or voice of the call, that is, in addition to the music or voice of the call in the above two cases, the audio source can also superimpose the voice of the outside world enhanced by the human voice. Signal. The external speech signal processed by the human voice enhancement can be obtained by the human voice enhancement filter in the structure shown in FIG. 2 a or FIG. 2 b , which will not be repeated here.

Step 1002 , performing noise reduction or transparent transmission processing on the audio source to obtain a speaker driving signal.

In a possible implementation, the fixed secondary path SP filter can be obtained through the CODEC, then the audio source is processed according to the fixed SP filter to obtain a filtered signal, and then the filtered signal is subjected to noise reduction or transparent transmission processing to obtain the speaker driver Signal. Among them, the CODEC can obtain the estimated SP filter according to the preset speaker drive signal and the ear canal signal picked up by the feedback FB microphone. The ear canal signal includes the residual noise signal inside the ear canal. When the signal obtained by the estimated SP filter and the When the difference signal of the ear canal signal is within the set range, the estimated SP filter is determined as a fixed SP filter. Optionally, when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within the set range, the cascaded second-order filter is obtained according to the target frequency response of the estimated SP filter and the preset frequency division requirement. According to the parameters of the cascaded second-order filter, the SP cascaded second-order filter is obtained, and the SP cascaded second-order filter is used as a fixed SP filter.

In a possible implementation, the adaptive SP filter can be obtained through the DSP chip, and then the audio source is processed according to the adaptive SP filter to obtain a filtered signal, and then the filtered signal is subjected to noise reduction or transparent transmission processing to obtain the speaker driver Signal. Among them, the DSP chip can obtain the real-time noise signal, and obtain the estimated SP filter according to the audio source and the real-time noise signal. When the difference signal between the signal obtained by the estimated SP filter and the real-time noise signal is within the set range, the estimated SP The filter is determined to be an adaptive SP filter. Optionally, the DSP chip can first obtain the external signal picked up by the FF microphone and the ear canal signal picked up by the FB microphone. The external signal includes the external noise signal and music or call voice, and the ear canal signal includes the residual noise signal inside the ear canal and music. Or call voice, and then obtain the voice signal picked up by the main microphone, and finally subtract the external signal and the ear canal signal from the voice signal to obtain a real-time noise signal.

For noise reduction processing and transparent transmission processing in this application, reference may be made to the foregoing embodiments, which will not be repeated here.

Step 1003: Divide the speaker driving signal into sub-audio signals of at least two frequency bands.

The frequency divider of the present application may be configured to divide the frequency of the speaker drive signal based on the main working frequency bands of the at least two speakers, so as to obtain sub-audio signals of at least two frequency bands corresponding to the main working frequency bands of the at least two speakers, and then Let each speaker play the sub audio signal of the corresponding frequency band, so that the speaker maintains the best frequency response when playing the sub audio signal transmitted to it. Adjacent frequency bands in the aforementioned at least two frequency bands partially overlap, or adjacent frequency bands in the at least two frequency bands do not overlap. For example, a crossover divides the speaker drive signal into high and low frequency bands, the high and low frequency bands are completely separated, and there is no overlap; or, the high and low frequency bands partially overlap. For another example, the frequency divider divides the speaker driving signal into three frequency bands: high, middle and low frequency. The high frequency band and the middle frequency band are completely separated without overlapping. Some frequency bands of the middle frequency band and the low frequency band overlap; or, the high frequency band, the middle frequency band and the low frequency band Complete separation, no overlap; or, high frequency and mid frequency bands are partially overlapping, mid frequency and low frequency bands are completely separated, no overlap.

The present application can control the frequency divider 42 to divide the frequency of the speaker driving signal in a preset manner by setting the parameters of the frequency divider 42 . For the implementation of frequency division, reference may be made to FIG. 6a to FIG. 6d , which will not be repeated here.

Step 1004: Play one of the sub audio signals of at least two frequency bands through at least two speakers respectively.

FIG. 11 is an exemplary structural diagram of a playback device for a TWS headset of the present application. As shown in FIG. 11 , the device 1100 of this embodiment can be applied to the TWS headset in the above-mentioned embodiment, and the device 1100 includes: an acquisition module 1101, Processing module 1102 , frequency dividing module 1103 and playing module 1104 . in,

The acquisition module 1101 is used to acquire an audio source, the audio source is the original music or call voice, or, the audio source includes the voice signal enhanced by the human voice and the original music or call voice; processing module 1102 , used to perform noise reduction or transparent transmission processing on the audio source to obtain a speaker drive signal; the frequency division module 1103 is used to divide the speaker drive signal into sub-audio signals of at least two frequency bands, the at least two Adjacent frequency bands in the frequency bands partially overlap, or, adjacent frequency bands in the at least two frequency bands do not overlap; the playing module 1104 is configured to play the sub audio signals of the at least two frequency bands through at least two speakers respectively. one.

In a possible implementation manner, the processing module 1102 is specifically configured to obtain a fixed secondary path SP filter through a codec CODEC; process the audio source according to the fixed SP filter to obtain a filtered signal; The speaker driving signal is obtained by performing noise reduction or transparent transmission processing on the filtered signal.

In a possible implementation manner, the processing module 1102 is specifically configured to obtain an estimated SP filter according to a preset speaker drive signal and an ear canal signal picked up by the feedback FB microphone, where the ear canal signal includes the ear canal Internal residual noise signal and the music or talking speech; when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within a set range, the estimated SP filter is determined as the fixed SP filter.

In a possible implementation manner, the processing module 1102 is further configured to, when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within a set range, according to the estimation The parameters of the cascaded second-order filter are obtained from the target frequency response of the SP filter and the preset frequency division requirements; the SP cascaded second-order filter is obtained according to the parameters of the cascaded second-order filter, and the SP is cascaded A second order filter acts as the fixed SP filter.

In a possible implementation manner, the processing module 1102 is specifically configured to obtain an adaptive SP filter through a digital signal processing DSP chip; process the audio source according to the adaptive SP filter to obtain a filtered signal; The speaker driving signal is obtained by performing noise reduction or transparent transmission processing on the filtered signal.

In a possible implementation manner, the processing module 1102 is specifically configured to obtain a real-time noise signal; obtain an estimated SP filter according to the audio source and the real-time noise signal; When the difference signal between the signal and the real-time noise signal is within a set range, the estimated SP filter is determined as the adaptive SP filter.

In a possible implementation manner, the processing module 1102 is specifically configured to acquire the external signal picked up by the feedforward FF microphone and the ear canal signal picked up by the feedback FB microphone, where the external signal includes external noise signals and the music Or call voice, the ear canal signal includes the residual noise signal inside the ear canal and the music or the call voice; obtain the voice signal picked up by the main microphone; subtract the external signal and the ear canal from the voice signal The signal obtains a signal difference; the estimated SP filter is obtained from the audio source and the signal difference.

The apparatus of this embodiment can be used to execute the technical solution of the method embodiment shown in FIG. 10 , and its implementation principle and technical effect are similar, and details are not repeated here.

In the implementation process, each step of the above method embodiments may be completed by a hardware integrated logic circuit in a processor or an instruction in the form of software. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other Programming logic devices, discrete gate or transistor logic devices, discrete hardware components. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the methods disclosed in the embodiments of the present application may be directly embodied as executed by a hardware coding processor, or executed by a combination of hardware and software modules in the coding processor. The software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art. The storage medium is located in the memory, and the processor reads the information in the memory, and completes the steps of the above method in combination with its hardware.

The memory mentioned in the above embodiments may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically programmable Erase programmable read-only memory (electrically EPROM, EEPROM) or flash memory. Volatile memory may be random access memory (RAM), which acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (direct rambus RAM, DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but not be limited to, these and any other suitable types of memory.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described systems, devices and units can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A true wireless stereo TWS earphone, characterized in that it includes: an audio signal processing path, a frequency divider and at least two speakers; wherein,

The output end of the audio signal processing path is connected with the input end of the frequency divider; the output end of the frequency divider is connected with the at least two speakers;

The audio signal processing path is configured to output a speaker drive signal after performing noise reduction or transparent transmission processing on the audio source; the audio source is original music or voice of a call; the voice signal and the original music or call voice;

The frequency divider is configured to divide the speaker drive signal into sub-audio signals of at least two frequency bands, the at least two frequency bands correspond to the main working frequency bands of the at least two speakers; the at least two frequency bands are Adjacent frequency bands in the frequency bands partially overlap, or adjacent frequency bands in the at least two frequency bands do not overlap;

The at least two speakers are configured to play corresponding sub audio signals.
The TWS headset according to claim 1, wherein the audio signal processing path comprises:

A secondary path SP filter configured to prevent the noise reduction or passthrough process from canceling the sound of the audio source in the event that the noise reduction or passthrough process is concurrent with the audio source.
The TWS headset according to claim 2, wherein the audio signal processing path further comprises: a feedback FB microphone and a feedback filter; wherein,

the FB microphone is configured to pick up the ear canal signal, the ear canal signal includes the residual noise signal inside the ear canal and the music or the voice of the call;

The SP filter is configured to input the audio source, process the audio source, and transmit the output signal to the feedback filter after superimposing the ear canal signal;

The feedback filter is configured to generate a signal for the noise reduction or transparent transmission processing, and the noise reduction or transparent transmission processed signal is one of the superimposed signals for generating the speaker driving signal.
The TWS headset according to claim 3, wherein the feedback FB microphone, the feedback filter and the SP filter are set in a codec CODEC.
The TWS earphone according to claim 2, wherein the SP filter is configured to input the audio source, process the audio source, and the output signal is a superposition of the speaker driving signal Signal.
The TWS earphone according to claim 5, wherein the SP filter is arranged in a digital signal processing DSP chip.
The TWS headset according to any one of claims 1-6, further comprising: a first digital-to-analog converter DAC; an input end of the first DAC is connected to an output end of the audio signal processing path , the output end of the first DAC is connected with the input end of the frequency divider;

the first DAC configured to convert the speaker drive signal from a digital form to an analog form;

Correspondingly, the frequency divider is an analog frequency divider.
The TWS headset according to any one of claims 1-6, further comprising: at least two second DACs; the input ends of the at least two second DACs are both connected to the output of the frequency divider terminals are connected, and the output terminals of the at least two second DACs are respectively connected to one of the at least two speakers;

the second DAC configured to convert one of the sub-audio signals of the at least two frequency bands from a digital form to an analog form;

Correspondingly, the frequency divider is a digital frequency divider.
The TWS earphone according to any one of claims 1-8, wherein the main working frequency bands of the at least two speakers are not identical.
The TWS earphone according to claim 9, wherein the at least two speakers include a moving coil speaker and a moving iron speaker.
The TWS earphone according to claim 9, wherein the at least two speakers include a moving coil speaker, a moving iron speaker, a micro-electromechanical system MEMS speaker, and a planar vibrating diaphragm.
A method for playing a true wireless stereo TWS headset, wherein the method is applied to the TWS headset according to any one of claims 1-11; the method comprises:

Acquiring an audio source, where the audio source is original music or call voice, or, the audio source includes a voice signal enhanced by human voice and the original music or call voice;

Perform noise reduction or transparent transmission processing on the audio source to obtain a speaker drive signal;

frequency-dividing the speaker drive signal into sub-audio signals of at least two frequency bands, and adjacent frequency bands in the at least two frequency bands partially overlap, or adjacent frequency bands in the at least two frequency bands do not overlap;

One of the sub audio signals of the at least two frequency bands is played respectively through at least two speakers.
The method according to claim 12, characterized in that, performing noise reduction or transparent transmission processing on the audio source to obtain a speaker driving signal, comprising:

Obtain the fixed secondary path SP filter through the codec CODEC;

The audio source is processed according to the fixed SP filter to obtain a filtered signal;

The speaker driving signal is obtained by performing noise reduction or transparent transmission processing on the filtered signal.
The method according to claim 13, wherein the obtaining the fixed secondary path SP filter through a codec CODEC comprises:

Obtain the estimated SP filter according to the preset speaker drive signal and the ear canal signal picked up by the feedback FB microphone, where the ear canal signal includes the residual noise signal inside the ear canal;

When the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within a set range, the estimated SP filter is determined as the fixed SP filter.
The method according to claim 14, wherein after obtaining the estimated SP filter according to the preset speaker drive signal and the ear canal signal picked up by the feedback FB microphone, the method further comprises:

When the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within the set range, the cascade two is obtained according to the target frequency response of the estimated SP filter and the preset frequency division requirement. parameters of the order filter;

The SP cascaded second-order filter is obtained according to the parameters of the cascaded second-order filter, and the SP cascaded second-order filter is used as the fixed SP filter.
The method according to claim 12, characterized in that, performing noise reduction or transparent transmission processing on the audio source to obtain a speaker driving signal, comprising:

Obtain adaptive SP filter through digital signal processing DSP chip;

The audio source is processed according to the adaptive SP filter to obtain a filtered signal;

The speaker driving signal is obtained by performing noise reduction or transparent transmission processing on the filtered signal.
The method according to claim 16, wherein the acquiring the adaptive SP filter through a digital signal processing DSP chip comprises:

Get real-time noise signal;

Obtaining an estimated SP filter from the audio source and the real-time noise signal;

When the difference signal between the signal obtained by the estimated SP filter and the real-time noise signal is within a set range, the estimated SP filter is determined as the adaptive SP filter.
The method according to claim 17, wherein the acquiring a real-time noise signal comprises:

Obtain the external signal picked up by the feedforward FF microphone and the ear canal signal picked up by the feedback FB microphone, the external signal includes the external noise signal and the music or the voice of the call, and the ear canal signal includes the residual noise signal inside the ear canal and the music or voice of the call;

Get the voice signal picked up by the main microphone;

The real-time noise signal is obtained by subtracting the external signal and the ear canal signal from the speech signal.
The method according to any one of claims 12-18, wherein the main operating frequency bands of the at least two speakers are not identical.
The method of claim 19, wherein the at least two speakers comprise a moving coil speaker and a moving iron speaker.
The method of claim 19, wherein the at least two loudspeakers comprise moving coil loudspeakers, moving iron loudspeakers, MEMS loudspeakers and planar vibrating diaphragms.
A playback device for a true wireless stereo TWS headset, wherein the device is applied to the TWS headset according to any one of claims 1-11; the device comprises:

an acquisition module, configured to acquire an audio source, where the audio source is original music or call voice, or, the audio source includes a voice signal enhanced by human voice and the original music or call voice;

a processing module, configured to perform noise reduction or transparent transmission processing on the audio source to obtain a speaker driving signal;

A frequency dividing module, configured to divide the speaker drive signal into sub-audio signals of at least two frequency bands, and adjacent frequency bands in the at least two frequency bands partially overlap, or, adjacent frequency bands in the at least two frequency bands frequency bands do not overlap;

The playing module is used for playing one of the sub audio signals of the at least two frequency bands through the at least two speakers respectively.
The device according to claim 22, wherein the processing module is specifically configured to obtain a fixed secondary path SP filter through a codec CODEC; and the audio source is obtained by processing the fixed SP filter according to the fixed SP filter. Filter the signal; perform noise reduction or transparent transmission processing on the filtered signal to obtain the speaker drive signal.
The device according to claim 23, wherein the processing module is specifically configured to obtain an estimated SP filter according to a preset speaker drive signal and an ear canal signal picked up by a feedback FB microphone, the ear canal signal Including the residual noise signal inside the ear canal and the music or talking speech; when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within a set range, the estimated SP is filtered is determined as the fixed SP filter.
The device according to claim 24, wherein the processing module is further configured to: when the difference signal between the signal obtained by the estimated SP filter and the ear canal signal is within a set range, according to The target frequency response of the estimated SP filter and the preset frequency division requirements are obtained to obtain the parameters of the cascaded second-order filter; according to the parameters of the cascaded second-order filter, the SP cascaded second-order filter is obtained, and the An SP cascaded second-order filter acts as the fixed SP filter.
The device according to claim 22, wherein the processing module is specifically configured to obtain an adaptive SP filter through a digital signal processing DSP chip; and the audio source is obtained by processing the adaptive SP filter according to the adaptive SP filter. Filter the signal; perform noise reduction or transparent transmission processing on the filtered signal to obtain the speaker drive signal.
The device according to claim 26, wherein the processing module is specifically configured to obtain a real-time noise signal; obtain an estimated SP filter according to the audio source and the real-time noise signal; When the difference signal between the signal obtained by the detector and the real-time noise signal is within a set range, the estimated SP filter is determined as the adaptive SP filter.
The device according to claim 27, wherein the processing module is specifically configured to acquire external signals picked up by the feedforward FF microphone and ear canal signals picked up by the feedback FB microphone, the external signals comprising external noise signals and For the music or call voice, the ear canal signal includes the residual noise signal inside the ear canal and the music or call voice; obtain the voice signal picked up by the main microphone; subtract the external signal and all the voice signals from the voice signal; Obtain the signal difference from the ear canal signal; obtain the estimated SP filter according to the audio source and the signal difference.
The device according to any one of claims 22-28, wherein the main working frequency bands of the at least two speakers are not identical.
30. The apparatus of claim 29, wherein the at least two speakers comprise a moving coil speaker and a moving iron speaker.
The apparatus of claim 29, wherein the at least two speakers comprise a moving coil speaker, a moving iron speaker, a MEMS speaker, and a planar vibrating diaphragm.
A computer-readable storage medium, characterized by comprising a computer program, which, when executed on a computer, causes the computer to execute the method of any one of claims 12-21.
A computer program, characterized in that, when the computer program is executed by a computer, it is used to execute the method of any one of claims 12-21.