Earphone call noise reduction processing method and device, earphone and DSP unit

Abstract

The invention discloses an earphone call noise reduction processing method and device, an earphone and a DSP unit. The method comprises the following steps: when a user calls, acquiring a signal FBANC picked up by a feedback microphone under the condition that an earphone ANC unit is turned on; inverse feedback noise reduction processing is carried out on the FBANC, and an inverse feedback noise reduction signal FBINVFB of a feedback microphone is acquired; carrying out inverse feed-forward noise reduction processing on the FBINVFB to obtain an inverse mixed noise reduction signal FBINV of a feedback microphone; and using the FBINV to replace the FBANC to execute earphone call noise reduction processing so as to remove the influence on a signal picked up by a feedback microphone under the condition that the ANC unit is turned on. According to the invention, the existing feedback microphone of the earphone is used for reducing the noise of the call, so that the earphone still has higher call definition in noisy and wind noise scenes, and the stable voice listening feeling of the opposite side of the call can be ensured.

Description

Technical Field

[0001] The present invention relates to the field of speech processing technology, and in particular to a method and device for earphone call noise reduction processing, an earphone and a DSP unit. Background Art

[0002] Headphones with active noise reduction (ANC) units are not limited to in-ear headphones, headphones, etc., and are usually provided with a feedforward microphone (ffmic) located outside the headphone and a feedback microphone (fbmic) located inside the cavity formed by the headphone and the ear canal and arranged near the headphone speaker. Using ffmic and fbmic, the ANC unit can provide a transparency function (transparency mode). The transparency function generally picks up the surrounding sounds, amplifies them appropriately, and mixes them into the audio being played. In this way, the user can hear the audio in the headphones and the surrounding sounds at the same time without having to take off the headphones. The transparency function can help users better integrate into the surrounding environment, for example, when running or cycling outdoors, they can more safely perceive the surrounding traffic sounds. In addition, when using headphones for phone calls, the transparency function also allows users to hear their own voices more clearly, so that they can better control their voice volume.

[0003] Using ffmic and fbmic, the ANC unit can also provide active noise reduction. There are three modes of active noise reduction: feedforward noise reduction, feedback noise reduction and hybrid noise reduction. It uses feedforward and / or feedback microphones to capture environmental noise, and generates reverse noise with similar amplitude and opposite phase to the noise through ANC filtering. Finally, the speaker emits this new noise, thereby reducing the interference of external noise.

[0004] In addition, headphones with ANC units are usually equipped with digital signal processing (DSP) units. Using ffmic and fbmic, the DSP unit can provide call noise reduction function. Call noise reduction is a noise reduction technology specifically for telephone call scenarios. It captures the call voice and uses digital signal processing technology to remove environmental noise and echo, and sends the processed language signal to the other end of the call, thereby improving the call clarity heard by the other end. Currently, conventional call noise reduction processing includes noise suppression (NS) of the input microphone signal, audio equalization processing (EQ, EQ is the abbreviation of equalizer), automatic gain control (AGC), etc.

[0005] In noisy and windy scenes, the signal-to-noise ratio (SNR) of the feedforward microphone used to receive external sound signals is low. If a single or multiple feedforward microphones outside the ear are used for call noise reduction, the call clarity is generally poor. In noisy and windy scenes, the in-ear microphone has an advantage of having a much higher SNR than the external ear microphone. Therefore, using the feedback microphone fbmic located in the cavity formed by the earphone and the ear canal for call noise reduction can achieve higher call clarity.

[0006] However, there are some problems with using fbmic for call noise reduction. For example, when the ANC unit turns on the transparent mode in a noisy scene, or when the ANC unit turns on the feedforward noise reduction or hybrid noise reduction mode in a scene with wind noise, the ear will become very noisy due to the introduction of strong ambient noise signals or external wind noise signals. The fbmic loses its high SNR advantage and cannot provide clear calls in noisy and windy scenes. Moreover, the voice signal picked up by the fbmic will also be affected by the change of the ANC unit mode. If the noise reduction mode changes during a call, such as changing from the transparent mode to the active noise reduction mode, the low-frequency power spectrum of the voice signal picked up by the fbmic will change, which will lead to inconsistency in the voice signal picked up by the fbmic, making the voice heard by the other party unstable.

[0007] In the prior art, in order to solve the problem of low call clarity in noisy and windy scenes, a bone conduction sensor is generally added to assist calls. It is not affected by the ANC unit and has a higher SNR in noisy and windy scenes. However, its disadvantages are also obvious: because the bone conduction sensor senses vibration signals, it is only sensitive to signals in the lower frequency band of the voice band, resulting in loss of the received voice signal and increasing the size and cost of the headset. Summary of the invention

[0008] The embodiments of the present invention provide a headset call noise reduction processing method and device, a headset and a DSP unit, which can use the existing feedback microphone of the headset to perform call noise reduction, thereby solving the problem of low call clarity in noisy and wind noise scenes.

[0009] According to a first aspect of the present invention, a method for processing noise reduction for earphone calls is provided, wherein the earphone comprises an ANC unit, a feedforward microphone located outside the earphone, and a feedback microphone located in a cavity formed by the earphone and an ear canal and arranged near the earphone speaker, and the method comprises:

[0010] When the user is talking, the signal FB picked up by the feedback microphone when the ANC unit is turned on is obtained ANC ;

[0011] About the FB ANCPerform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB ;

[0012] About the FB INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV ;

[0013] Use the FB INV Replace the FB ANC To perform headset call noise reduction processing to remove the influence of the signal picked up by the feedback microphone when the ANC unit is turned on.

[0014] According to a second aspect of the present invention, a headset call noise reduction processing device is provided, wherein the headset comprises an ANC unit, a feedforward microphone located outside the headset, and a feedback microphone located in a cavity formed by the headset and the ear canal and arranged near the headset speaker, and the device comprises:

[0015] A feedback microphone signal acquisition unit is used to acquire the signal FB picked up by the feedback microphone when the ANC unit is turned on when the user is talking. ANC ;

[0016] The reverse feedback noise reduction processing unit is used to ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB ;

[0017] The inverse feedforward noise reduction processing unit is used to INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV ;

[0018] A subsequent processing unit is used to use the FB INV Replace the FB ANC To perform headset call noise reduction processing to remove the influence of the signal picked up by the feedback microphone when the ANC unit is turned on.

[0019] According to the third aspect of the present invention, there is provided an earphone, comprising an ANC unit, a feedforward microphone located outside the earphone, and a feedback microphone located in a cavity formed by the earphone and the ear canal and arranged near the earphone speaker. The earphone also comprises a DSP unit. When a user is talking on a call, the DSP unit processes the signal picked up by the feedback microphone when the ANC unit is turned on using the aforementioned earphone call noise reduction processing method.

[0020] According to a fourth aspect of the present invention, a DSP unit for headphones is provided, the DSP unit comprising the aforementioned headphone call noise reduction processing device.

[0021] The beneficial effects of the embodiments of the present invention are:

[0022] In various embodiments of the present invention, when a user is talking on a call, a signal FB picked up by a feedback microphone when the headset ANC unit is turned on is obtained. ANC , then on the FB ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB , then the FB INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV In order to use the FB INV Replace the FB ANC To perform headset call noise reduction processing. After the reverse mixing noise reduction, the part of the signal picked up by the feedback microphone affected by the ANC unit is removed, and the obtained FB INV It is equivalent to the signal picked up by the feedback microphone when the headset ANC unit is turned off. Therefore, when the user is talking, the FB INV Replace the FB ANC To perform headset call noise reduction processing, it can remove the influence of the headset ANC unit on the signal picked up by the feedback microphone when it is turned on, so that no matter the headset's ANC unit turns on the transparency mode in a noisy scene or turns on the feedforward noise reduction or other modes in a wind noise scene, the consistency of the signal picked up by the feedback microphone can be guaranteed, and a high SNR is always maintained, ensuring high call clarity during calls, and can ensure a stable voice hearing experience on the other party, thereby improving the usability of the feedback microphone in call noise reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings. In the drawings:

[0024] Figure 1 A schematic diagram showing a flow chart of a method for processing earphone call noise reduction according to an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the ANC unit processing logic of a headset according to an embodiment of the present invention is shown;

[0026] Figure 3A schematic diagram showing the processing logic of the DSP unit of the headset according to one embodiment of the present invention is shown;

[0027] Figure 4 A schematic diagram showing the structure of an earphone call noise reduction processing device according to an embodiment of the present invention;

[0028] Figure 5 A schematic structural diagram of an earphone according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0029] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. These embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0030] First of all, it should be noted that the earphones in the embodiments of the present invention include not only an ANC unit, a feedforward microphone ffmic located outside the earphone, a feedback microphone fbmic located in a cavity formed by the earphone and the ear canal and arranged near the earphone speaker, but also a DSP unit. Using ffmic and fbmic, the ANC unit can provide active noise reduction and transparency functions, and the DSP unit can provide call noise reduction. Specifically, the active noise reduction function of the ANC unit involves eliminating the noise leaking into the ear from the external environmental noise as much as possible, and the call noise reduction function of the DSP unit involves eliminating the noise in the uplink call signal as much as possible, so that the voice signal heard by the other end of the call is clearer. It is easy to understand that when a user makes a voice call in a noisy external environment (for example, in a subway or in a noisy open-air environment), the ANC unit may be in an active noise reduction on state.

[0031] In addition, various signals in this article refer to frequency domain signals, that is, the signals picked up by the microphone are transformed from the time domain Fourier transform to the frequency domain.

[0032] Figure 1 FIG. 1 is a flow chart showing a method for reducing noise during a headset call according to an embodiment of the present invention. Figure 1 As shown, the headset call noise reduction processing method of the present invention includes the following steps S110 to S140:

[0033] Step S110, when the user is on a call, obtain the signal FB picked up by the feedback microphone when the headset ANC unit is turned on ANC .

[0034] Step S120, the FB ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB .

[0035] Step S130: INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV .

[0036] Step S140, using the FB INV Replace the FB ANC To perform headset call noise reduction processing to remove the impact of the signal picked up by the feedback microphone when the ANC unit is turned on.

[0037] Figure 2 FIG. 1 is a schematic diagram showing the processing logic of the ANC unit of the headset according to an embodiment of the present invention. Figure 3 A schematic diagram of the processing logic of the DSP unit of the headset according to an embodiment of the present invention is shown.

[0038] Combine the following Figure 2 and Figure 3 ,right Figure 1 The above steps are described in detail.

[0039] Since the feedforward microphone ffmic is located outside the headset, its pickup signal is not affected by whether the ANC unit is turned on or not. The signal picked up by the feedforward microphone is modeled as follows:

[0040] FF = N + S + W (1)

[0041] Among them, FF is the signal picked up by the feedforward microphone, N is the extra-ear noise signal, S is the user's voice signal, and when the user is not speaking, S=0; W is the signal caused by the extra-ear wind noise on the feedforward microphone, and when there is no wind outside the ear, W=0.

[0042] In noisy or windy scenes, the signal-to-noise ratio (SNR) of ffmic may be very low, and if used directly, it is impossible to get a clear call. However, the signal-to-noise ratio (SNR) of the feedback microphone fbmic located in the cavity formed by the earphone and the ear canal is still high, which can provide sufficient clarity for the call.

[0043] Since the feedback microphone fbmic is located in the cavity formed by the earphone and the ear canal, the signal it picks up is affected by whether the ANC unit is turned on.

[0044] When the headphone ANC unit is turned off, the signal picked up by the feedback microphone is modeled as follows:

[0045] FB OFF = FF*P + S0 + W0 (2)

[0046] Among them, FB OFFis the signal picked up by the feedback microphone when the headphone ANC unit is turned off, FF is the signal picked up by the feedforward microphone, and P is the acoustic path transfer function of the external sound signal leaking into the ear when the headphone ANC unit is turned off; S0 is the voice signal in the ear when the user speaks, and when the user does not speak, S0=0; W0 is the interference signal in the ear caused by the wind vibrating the headphone during wind noise, and when there is no wind outside the ear, W0=0; S is related to S0, W0 is not related to W, and W is usually much greater than W0. Therefore, when the ANC unit turns on feedforward noise reduction or mixed noise reduction, obvious wind noise will appear in the ear, making the signal-to-noise ratio SNR of fbmic lower.

[0047] See also Figure 2 , when the headphone ANC unit is turned on, the signal picked up by the feedback microphone is modeled:

[0048] FB ANC = (FF*H FF *G + FB OFF ) / (1-H FB *G) (3)

[0049] Among them, FB ANC is the signal picked up by the feedback microphone when the headphone ANC unit is turned on, FF is the signal picked up by the feedforward microphone, and H FF is the frequency response curve of the feedforward filter, H FB is the frequency response curve of the feedback filter, FB OFF is the signal picked up by the feedback microphone when the headphone ANC unit is turned off, and G is the transfer function from the headphone speaker to the feedback microphone when the headphone ANC unit is turned off. It is easy for a person skilled in the art to understand that for a given noise reduction headphone, its H FF , H FB are all known parameters, which are related to the parameters of the filter. These parameters can be preset or adaptively adjusted as needed during use. G can also be estimated by prior measurement or real-time measurement, as described below.

[0050] In formula (3), if H FF =0 corresponds to the mode in which the ANC unit turns off the feedforward noise reduction; if H FB =0 corresponds to the mode in which the ANC unit turns off feedback noise reduction; if H FF ≠0 and H FB ≠0 corresponds to the ANC unit in hybrid noise reduction mode; if H FF = 0 and H FB =0 corresponds to the mode in which the ANC unit turns off active noise reduction.

[0051] The user's in-ear voice signal S0 will be affected by the change of the ANC unit mode. Once the ANC unit changes its mode, for example, from feedback noise reduction mode or hybrid noise reduction mode to transparent mode or feedforward noise reduction mode, the low-frequency power spectrum in the voice signal picked up by the fbmic will change, which will lead to inconsistency in the user's voice signal picked up by the fbmic, making the voice heard by the other party unstable and affecting the experience.

[0052] See also Figure 3 , the FB obtained from formula (3) ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB as follows:

[0053] FB INVFB = FB ANC *(1-H FB *G') (4)

[0054] Among them (1-H FB *G') forms an inverse feedback noise reduction filter. FB ANC It is the signal picked up by the feedback microphone when the headphone ANC unit is turned on. FB is the frequency response curve of the feedback filter, G' is the estimated value of G, and G is the transfer function from the headphone speaker to the feedback microphone when the headphone ANC unit is turned off. G' can be a preset value, such as the average value of multi-person data measured in the laboratory in advance; it can also be an online estimated value, such as estimating G' based on the headphone speaker input signal and the signal picked up by the feedback microphone when there is an audio signal in the headphone speaker and the ANC unit is turned off.

[0055] Still see Figure 3 , the FB obtained from formula (4) INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV as follows:

[0056] FB INV = FB INVFB -FF*H FF * G' (5)

[0057] Among them, H FF *G' forms an inverse feedforward noise reduction filter. FB INVFB is the reverse feedback noise reduction signal of the feedback microphone, FF is the signal picked up by the feedforward microphone, H FF is the frequency response curve of the feedforward filter, G' is the estimated value of G, and G is the transfer function from the headphone speaker to the feedback microphone when the headphone ANC unit is turned off.

[0058] The FB of the above formula (4) INVFBThe FB of formula (3) ANC Substituting the expressions of into formula (5) one by one, we get:

[0059] FB INV =FB INVFB -FF*H FF *G'

[0060] =FB ANC *(1-H FB *G')-FF*H FF *G'

[0061] =[(FF*H FF *G+FB OFF ) / (1-H FB *G)]*(1-H FB *G')-FF*H FF *G'

[0062] Considering that G' is an estimate of G, G'≈G, therefore:

[0063] (1-H FB *G)≈(1-H FB *G'), FF*H FF *G≈FF*H FF *G'

[0064] Then we get: FB INV ≈FB OFF

[0065] That is to say, when the ANC unit is turned on, the signal FB picked up by fbmic is ANC After inverse hybrid denoising (first inverse feedback denoising, then inverse feedforward denoising), the inverse hybrid denoising signal FB is obtained INV , close to the signal FB picked up by fbmic when the ANC unit is turned off OFF .

[0066] It can be seen that in noisy scenes, when the ANC unit turns on the transparency mode, the signal-to-noise ratio (SNR) of fbmic is very low, but after inverse hybrid noise reduction, the SNR of the obtained signal is close to the SNR when the ANC unit is turned off, so that the SNR advantage of fbmic is retained, and the call still has high clarity. Similarly, in wind noise scenes, when the ANC unit turns on the feedforward noise reduction mode or the hybrid noise reduction mode, the signal-to-noise ratio (SNR) of fbmic is also very low, but after inverse hybrid noise reduction, the SNR of the obtained signal is close to the SNR when the ANC unit is turned off, so that the SNR advantage of fbmic is retained, and the call still has high clarity.

[0067] If the ANC unit changes mode during a call, for example, from transparent mode to active noise reduction mode (feedforward noise reduction mode or hybrid noise reduction mode), the low-frequency power spectrum of the user's voice in the signal picked up by the fbmic will change, which will lead to inconsistency in the voice signal picked up by the fbmic, making the voice heard by the other party unstable and affecting the experience. However, after the above-mentioned inverse hybrid noise reduction, the obtained inverse hybrid noise reduction signal FB INV FB signal picked up by fbmic when the ANC unit is turned off OFF , so that the voice signal picked up by the fbmic is basically no longer affected by the activation of the ANC unit, so that the consistency of the voice signal picked up by the feedback microphone is guaranteed, thereby ensuring a stable voice hearing experience for the other party on the call.

[0068] In summary, when a user is on a call, the headset call noise reduction processing method of the present application is used to first obtain the signal FB picked up by the feedback microphone when the headset ANC unit is turned on. ANC , then on the FB ANC Perform reverse feedback noise reduction processing and reverse feedforward noise reduction processing in sequence to obtain the reverse mixed noise reduction signal FB of the feedback microphone INV and use the FB INV Replace the current FB ANC To perform subsequent headset call noise reduction processing. It is easy for technicians in the relevant field to understand that the subsequent call noise reduction processing usually includes conventional processing contents such as noise suppression (NS) of the input microphone signal, audio equalization processing (EQ), automatic gain control (AGC), etc. Since this part of the processing is not the focus of this application, it will not be described here one by one. The voice signal after the subsequent headset call noise reduction processing is sent to the call partner as the uplink call voice signal.

[0069] It can be seen that after the inverse mixing noise reduction, the part of the signal picked up by the feedback microphone affected by the ANC unit is removed, and the obtained FB INV It is equivalent to feeding back the signal picked up by the microphone when the ANC unit of the headset is turned off. Therefore, when making a call, use the FB INV Replace the FB ANC To perform headset call noise reduction processing, it can remove the impact of the signal picked up by the feedback microphone when the headset ANC unit is turned on, so that no matter the headset turns on the transparency mode in a noisy scene or turns on the feedforward noise reduction or other modes in a wind noise scene, the consistency of the signal picked up by the feedback microphone can be guaranteed, and a high SNR is always maintained, ensuring high call clarity during calls, and can ensure a stable voice hearing experience of the other party on the call, improving the usability of the feedback microphone in call noise reduction.

[0070] Belonging to the same technical concept as the aforementioned earphone call noise reduction processing method, an embodiment of the present invention further provides an earphone call noise reduction processing device. Figure 4 FIG. 1 is a schematic diagram showing a structure of an earphone call noise reduction processing device according to an embodiment of the present invention. Figure 4 As shown, the device of the present invention comprises:

[0071] The feedback microphone signal acquisition unit 410 is used to acquire the signal FB picked up by the feedback microphone when the headset ANC unit is turned on when the user is talking. ANC ;

[0072] The reverse feedback noise reduction processing unit 420 is used to ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB ;

[0073] The reverse feedforward noise reduction processing unit 430 is used to INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV ;

[0074] The subsequent processing unit 440 is used to use the FB INV Replace the FB ANC The subsequent headset call noise reduction processing is performed to remove the influence of the ANC unit on the signal picked up by the feedback microphone when the ANC unit is turned on. The voice signal processed by the subsequent processing unit 440 is sent to the call peer as an uplink call voice signal.

[0075] In one embodiment of the present invention, the inverse feedback noise reduction processing unit 420 is specifically used for:

[0076] The inverse feedback noise reduction signal FB of the feedback microphone is obtained according to the following formula: INVFB :

[0077] FB INVFB =FB ANC *(1-H FB *G');

[0078] Among them (1-H FB *G') forms an inverse feedback noise reduction filter, H FB is the frequency response curve of the feedback filter, G' is the estimated value of G, and G is the transfer function from the headphone speaker to the feedback microphone when the ANC unit is turned off.

[0079] In one embodiment of the present invention, the inverse feedforward noise reduction processing unit 430 is specifically used for:

[0080] The inverse mixed noise reduction signal FB of the feedback microphone is obtained according to the following formula: INV :

[0081] FB INV =FB INVFB -FF*H FF *G';

[0082] Among them, H FF *G' forms an inverse feedforward noise reduction filter, FF is the signal picked up by the feedforward microphone, H FF This is the frequency response curve of the feedforward filter.

[0083] The implementation process of each unit module in the headset call noise reduction processing device of the present invention can be referred to the above-mentioned method embodiment, which will not be repeated here.

[0084] Belonging to the same technical concept as the aforementioned earphone call noise reduction processing method and device, an embodiment of the present invention further provides an earphone. Figure 5 FIG. 1 is a schematic diagram showing the structure of an earphone provided by an embodiment of the present invention. Figure 5 The headset provided by the present invention includes: a speaker, an ANC unit, a feedforward microphone located outside the headset, a feedback microphone located in a cavity formed by the headset and the ear canal and arranged near the headset speaker, and a DSP unit. When the user is talking, the DSP unit uses the above-mentioned headset call noise reduction processing method to process the signal picked up by the feedback microphone when the ANC unit is turned on. Specifically, the signal FB picked up by the feedback microphone when the ANC unit is turned on is obtained. ANC , on the FB ANC Perform reverse feedback noise reduction processing and reverse feedforward noise reduction processing in sequence to obtain the reverse mixed noise reduction signal FB of the feedback microphone INV , then use the FB INV Replace the FB ANC To perform headset call noise reduction processing to remove the impact of the signal picked up by the feedback microphone when the ANC unit is turned on.

[0085] At the hardware level, the headset also includes a memory for storing computer program instructions, and a wireless communication module not limited to Bluetooth and WIFI. These units or modules in the headset can be interconnected through an internal bus, which can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0086] An embodiment of the present invention further provides a DSP unit for earphones, wherein the DSP unit includes the aforementioned earphone call noise reduction processing device.

[0087] It will be appreciated by those skilled in the art that the various embodiments of the present invention may be provided as methods, devices, headphones or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or a combination of software and hardware embodiments.

[0088] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "includes..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0089] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for processing noise reduction during a headset call, wherein the headset comprises an active noise reduction (ANC) unit, a feedforward microphone located outside the headset, and a feedback microphone located in a cavity formed by the headset and an ear canal and arranged near a headset speaker. It is characterized in that The method comprises: When the user is talking, the signal FB picked up by the feedback microphone when the ANC unit is turned on is obtained ANC ; About the FB ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB ; About the FB INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV ; Use the FB INV Replace the FB ANC To perform headset call noise reduction processing to remove the influence of the signal picked up by the feedback microphone when the ANC unit is turned on.

2. The method according to claim 1, It is characterized in that The FB ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB ,include: The reverse feedback noise reduction signal FB of the feedback microphone is obtained according to the following formula: INVFB : FB INVFB =FB ANC *(1-H FB *G’); Among them (1-H FB *G') forms an inverse feedback noise reduction filter, H FB is the frequency response curve of the feedback filter, G' is the estimated value of G, and G is the transfer function from the headphone speaker to the feedback microphone when the ANC unit is turned off.

3. According to the method of claim 2, It is characterized in that The FB INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV ,include: The inverse mixed noise reduction signal FB of the feedback microphone is obtained according to the following formula: INV : FB INV =FB INVFB -FF*H FF *G’; Among them, H FF *G' forms an inverse feedforward noise reduction filter, FF is the signal picked up by the feedforward microphone, H FF This is the frequency response curve of the feedforward filter.

4. An earphone call noise reduction processing device, the earphone comprising an ANC unit, a feedforward microphone located outside the earphone, and a feedback microphone located in a cavity formed by the earphone and the ear canal and arranged near the earphone speaker, It is characterized in that The device comprises: A feedback microphone signal acquisition unit is used to acquire the signal FB picked up by the feedback microphone when the ANC unit is turned on when the user is talking. ANC ; The reverse feedback noise reduction processing unit is used to ANC Perform reverse feedback noise reduction processing to obtain the reverse feedback noise reduction signal FB of the feedback microphone INVFB ; The inverse feedforward noise reduction processing unit is used to INVFB Then perform inverse feedforward noise reduction processing to obtain the inverse mixed noise reduction signal FB of the feedback microphone INV ; A subsequent processing unit is used to use the FB INV Replace the FB ANC To perform headset call noise reduction processing to remove the influence of the signal picked up by the feedback microphone when the ANC unit is turned on.

5. The device according to claim 4, It is characterized in that The inverse feedback noise reduction processing unit is specifically used for: The reverse feedback noise reduction signal FB of the feedback microphone is obtained according to the following formula: INVFB : FB INVFB =FB ANC *(1-H FB *G’); Among them (1-H FB *G') forms an inverse feedback noise reduction filter, H FB is the frequency response curve of the feedback filter, G' is the estimated value of G, and G is the transfer function from the headphone speaker to the feedback microphone when the ANC unit is turned off.

6. The device according to claim 5, It is characterized in that The inverse feedforward noise reduction processing unit is specifically used for: The inverse mixed noise reduction signal FB of the feedback microphone is obtained according to the following formula: INV : FB INV =FB INVFB -FF*H FF *G’; Among them, H FF *G' forms an inverse feedforward noise reduction filter, FF is the signal picked up by the feedforward microphone, H FF This is the frequency response curve of the feedforward filter.

7. An earphone comprising an active noise reduction (ANC) unit, a feedforward microphone located outside the earphone, and a feedback microphone located in a cavity formed by the earphone and the ear canal and arranged near the earphone speaker, It is characterized in that The headset also includes a digital signal processing (DSP) unit. When the user is on a call, the DSP unit processes the signal picked up by the feedback microphone when the ANC unit is turned on using the headset call noise reduction processing method according to any one of claims 1 to 3.

8. A DSP unit for headphones, It is characterized in that The DSP unit includes the earphone call noise reduction processing device according to any one of claims 4 to 6.

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