Bone conduction microphones and noise reduction methods

Abstract

This application discloses a bone conduction microphone and a noise reduction method, belonging to the field of electronic technology. The bone conduction microphone includes: a housing, a piezoelectric sensor, a vibrating element, a circuit board, a microelectromechanical system (MEMS) chip, and an application-specific integrated circuit (ASIC) chip. The housing and the circuit board are connected to form a first cavity. The vibrating element, the MEMS chip, and the ASIC chip are all disposed in the first cavity. The MEMS chip and the ASIC chip are both electrically connected to the circuit board, and the MEMS chip is electrically connected to the ASIC chip. The piezoelectric sensor is disposed on the side of the housing facing the first cavity and is electrically connected to the circuit board.

Description

Technical Field

[0001] This application belongs to the field of electronic technology, specifically relating to a bone conduction microphone and a noise reduction method. Background Technology

[0002] Bone conduction technology effectively solves the problem of environmental noise affecting sound transmission through the air. It uses bone conduction microphones to pick up vibration signals from the human skeleton to achieve the shielding of environmental noise.

[0003] However, the vibration signal of bone conduction microphones in related technologies suffers energy loss when passing through the vibrating element, resulting in low sensitivity and low signal-to-noise ratio when receiving small vibration signals. Moreover, bone conduction microphones in related technologies are also difficult to effectively eliminate noise such as skin friction noise, strong wind noise during extreme sports, and noise introduced by chewing, resulting in poor call quality. Summary of the Invention

[0004] This application provides a bone conduction microphone and a noise reduction method, which can solve the problem of low sensitivity of bone conduction microphones in the prior art.

[0005] In a first aspect, embodiments of this application provide a bone conduction microphone, comprising: a housing, a piezoelectric sensor, a vibrating element, a circuit board, a microelectromechanical system (MEMS) chip, and an application-specific integrated circuit (ASIC) chip.

[0006] The housing is connected to the circuit board to form a first cavity. The vibrating element, the microelectromechanical system chip, and the dedicated integrated circuit chip are all disposed in the first cavity. The microelectromechanical system chip and the dedicated integrated circuit chip are electrically connected to the circuit board. The microelectromechanical system chip and the dedicated integrated circuit chip are electrically connected.

[0007] The piezoelectric sensor is disposed on the side of the housing facing the first cavity, and the piezoelectric sensor is electrically connected to the circuit board.

[0008] Secondly, embodiments of this application provide a noise reduction method applied to the bone conduction microphone described in the first aspect, the noise reduction method comprising:

[0009] Acquire microelectromechanical system (MEMS) signals and piezoelectric signals, wherein the MEMS signals are signals output by the MEMS chip and processed by a dedicated integrated circuit (DAC) chip, and the piezoelectric signals are signals output by the piezoelectric sensor and processed by the DAC chip;

[0010] When both the microelectromechanical system signal and the piezoelectric signal are less than the speech signal threshold, a first difference between the microelectromechanical system signal and the piezoelectric signal is obtained.

[0011] Based on the first difference, the first noise-reduced bone conduction speech signal is obtained;

[0012] When both the microelectromechanical system signal and the piezoelectric signal are greater than the speech signal threshold, a second difference between the piezoelectric signal and the microelectromechanical system signal is obtained;

[0013] Based on the second difference, the second noise-reduced bone conduction speech signal is obtained;

[0014] The first or second noise-reduced bone conduction speech signal is subjected to noise reduction processing to obtain enhanced speech.

[0015] Thirdly, embodiments of this application provide a noise reduction device applied to the bone conduction microphone described in the first aspect, the noise reduction device comprising:

[0016] The first acquisition module is used to acquire microelectromechanical system (MEMS) signals and piezoelectric signals. The MEMS signals are signals output by the MEMS chip and processed by a dedicated integrated circuit (DIC) chip. The piezoelectric signals are signals output by the piezoelectric sensor and processed by the DIC chip.

[0017] The second acquisition module is used to acquire a first difference between the microelectromechanical system signal and the piezoelectric signal when both the microelectromechanical system signal and the piezoelectric signal are less than the voice signal threshold.

[0018] The first determining module is used to obtain the first noise-reduced bone conduction speech signal based on the first difference.

[0019] The third acquisition module is used to acquire a second difference between the piezoelectric signal and the microelectromechanical system signal when both the microelectromechanical system signal and the piezoelectric signal are greater than the voice signal threshold.

[0020] The second determining module is used to obtain the second noise-reduced bone conduction speech signal based on the second difference.

[0021] The noise reduction module is used to perform noise reduction processing on the first noise-reduced bone conduction speech signal or the second noise-reduced bone conduction speech signal to obtain enhanced speech.

[0022] Fourthly, embodiments of this application provide a bone conduction microphone, the bone conduction microphone including a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the method described in the second aspect.

[0023] Fifthly, embodiments of this application provide a readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the second aspect.

[0024] In a sixth aspect, embodiments of this application provide a chip, the chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the method described in the second aspect.

[0025] In a seventh aspect, embodiments of this application provide a computer program product / program product stored in a non-transient storage medium, the computer program / program product being executed by at least one processor to implement the steps of the method described in the second aspect.

[0026] In this embodiment, the bone conduction microphone includes a housing, a piezoelectric sensor, a vibrating element, a circuit board, a microelectromechanical system (MEMS) chip, and an application-specific integrated circuit (ASIC) chip. The housing and the circuit board are connected to form a first cavity. The vibrating element, the MEMS chip, and the ASIC chip are all disposed in the first cavity. The MEMS chip and the ASIC chip are electrically connected to the circuit board, and the MEMS chip is electrically connected to the ASIC chip. The piezoelectric sensor is disposed on the side of the housing facing the first cavity and is electrically connected to the circuit board. This embodiment adds a piezoelectric sensor between the vibrating element and the housing. The piezoelectric sensor picks up vibration signals passing between the vibrating elements, thereby improving the bone conduction microphone's ability to pick up small vibration signals and increasing the sensitivity of the bone conduction microphone. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a bone conduction microphone provided in one embodiment of this application;

[0028] Figure 2 This is a structural block diagram of the connection between a MEMS chip and an ASIC chip provided in one embodiment of this application;

[0029] Figure 3 This is a structural block diagram of a processor provided in one embodiment of this application;

[0030] Figure 4 This is a structural block diagram of a noise reduction chip provided in one embodiment of this application;

[0031] Figure 5 This is a schematic diagram of the signal processing of a first noise reduction module provided in one embodiment of this application;

[0032] Figure 6 This is a schematic diagram of the signal processing of another first noise reduction module provided in one embodiment of this application;

[0033] Figure 7 This is a structural block diagram of a second noise reduction module provided in one embodiment of this application;

[0034] Figure 8 This is a schematic flowchart of a noise reduction method provided in one embodiment of this application;

[0035] Figure 9 This is a structural block diagram of a noise reduction device provided in one embodiment of this application;

[0036] Figure 10 This is a schematic diagram of a bone conduction microphone provided in one embodiment of this application.

[0037] in,

[0038] 21-Housing, 22-Piezoelectric sensor, 23-Mass block, 24-Elastic diaphragm, 25-Wire, 26-Circuit board, 27-MEMS chip, 28-ASIC chip. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0040] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0041] The following is in conjunction with the appendix Figures 1 to 10 The present application provides a detailed description of a bone conduction microphone and noise reduction method through specific embodiments and application scenarios.

[0042] like Figures 1 to 7As shown, this application provides a bone conduction microphone, which may include a housing 21, a piezoelectric sensor 22, a vibrating element, a circuit board 26, a micro-electro-mechanical system (MEMS) chip 27, and an application-specific integrated circuit (ASIC) chip 28.

[0043] The housing is connected to the circuit board to form a first cavity. The vibrating element, MEMS chip and ASIC chip are all disposed in the first cavity. The MEMS chip and ASIC chip are electrically connected to the circuit board. The MEMS chip and ASIC chip are electrically connected. The piezoelectric sensor is disposed on the side of the housing facing the first cavity and is electrically connected to the circuit board.

[0044] The piezoelectric sensor can be attached to the side of the housing facing the first cavity using epoxy or silicone adhesive, or it can be positioned on the same side of the housing in other ways, depending on the actual application. The piezoelectric sensor and the circuit board can be electrically connected via conductive leads.

[0045] In this embodiment, the bone vibration signal is transmitted to the voltage sensor and the vibrating component through the housing. The signal picked up by the voltage sensor is transmitted to the circuit board through conductive leads, and then picked up by the MEMS chip to generate an electrical signal. The signal is then amplified, filtered, and processed by the ASIC chip. The vibrating component causes vibration, thereby generating air pressure changes, which are then picked up by the MEMS chip to generate an electrical signal. The signal is then amplified, filtered, and processed by the ASIC chip.

[0046] In this embodiment, the bone conduction microphone includes a housing, a piezoelectric sensor, a vibrating element, a circuit board, a microelectromechanical system (MEMS) chip, and an application-specific integrated circuit (ASIC) chip. The housing and the circuit board are connected to form a first cavity. The vibrating element, the MEMS chip, and the ASIC chip are all disposed in the first cavity. The MEMS chip and the ASIC chip are electrically connected to the circuit board, and the MEMS chip is electrically connected to the ASIC chip. The piezoelectric sensor is disposed on the side of the housing facing the first cavity and is electrically connected to the circuit board. This embodiment adds a piezoelectric sensor between the vibrating element and the housing. The piezoelectric sensor picks up vibration signals passing between the vibrating elements, thereby improving the bone conduction microphone's ability to pick up small vibration signals and increasing the sensitivity of the bone conduction microphone.

[0047] In one possible embodiment of this application, the circuit board includes a first board body, a second board body, a third board body, and a fourth board body. The first board body, the second board body, the third board body, and the fourth board body form a second cavity. The first board body and the second board body are disposed opposite each other. The first board body is disposed on the side of the second board body away from the housing. A first hole is provided on the second board body. The MEMS chip 27 and the ASIC chip 28 are both disposed on the side of the second board body facing the first board body, and the MEMS chip is disposed facing the first hole. The vibrating element is disposed on the side of the second board body facing the housing, and the vibrating element is disposed facing the first hole.

[0048] The circuit board can be a printed circuit board (PCB).

[0049] In this embodiment, the bone vibration signal is transmitted to the vibrating element through the housing. The vibrating element vibrates, generating sound waves. These sound waves propagate through the first hole to the diaphragm of the MEMS chip, where they are picked up and converted into electrical signals. These signals are then amplified, filtered, and processed by the ASIC chip. By placing the vibrating element and the MEMS chip on opposite sides of the first hole on the second board, the sound waves generated by the vibrating element can be received by the MEMS chip and converted into electrical signals. The first hole allows for better reception of the sound waves by the MEMS chip, improving the accuracy of signal reception.

[0050] In one possible embodiment of this application, the vibrating element includes a mass block 23 and an elastic diaphragm 24. The elastic diaphragm is disposed on the second plate by a support member, and the mass block is disposed on the side of the elastic diaphragm away from the second plate.

[0051] In this embodiment, an elastic diaphragm and a mass block disposed on the elastic diaphragm are used to form a vibrating element. When the bone vibration signal is transmitted to the vibrating element through the shell, the small size and large mass of the mass block can better convert the bone vibration signal into the vibration of the elastic diaphragm. The vibration of the elastic diaphragm generates sound waves, which are transmitted to the diaphragm of the MEMS chip and then picked up by the MEMS chip and converted into electrical signals, thereby improving the accuracy of the MEMS chip in receiving signals.

[0052] In one possible embodiment of this application, the piezoelectric sensor 22 can be electrically connected to the second plate via a wire 25. Using a wire allows for better transmission of the signal received by the piezoelectric sensor to the second plate, and subsequently to the MEMS chip.

[0053] In one possible implementation of this application, the MEMS chip may include a MEMS backplate and a MEMS diaphragm.

[0054] The MEMS back electrode plate includes a first MEMS back electrode plate and a second MEMS back electrode plate. The first MEMS back electrode plate and the second MEMS back electrode plate are respectively disposed on both sides of the first hole. The MEMS diaphragm is electrically connected to the second plate body through the first MEMS back electrode plate and the second MEMS back electrode plate.

[0055] Among them, the MEMS diaphragm is used to receive the sound waves generated by the vibration of the vibrating component.

[0056] In this embodiment, the MEMS diaphragm is positioned facing the first hole of the second plate via a first MEMS back electrode plate and a second MEMS back electrode plate to receive sound waves generated by the vibration of the vibrating element.

[0057] like Figure 2 As shown, in one possible embodiment of this application, the ASIC chip includes a charge pump, a bandgap reference, a first amplifier, a second amplifier, and a low dropout regulator (LDO).

[0058] The bandgap reference source has its input terminal connected to an external power supply terminal, its output terminal connected to the input terminal of a charge pump, and its output terminal connected to a MEMS diaphragm. The external power supply terminal is used to power the MEMS chip. The low-dropout linear regulator has its input terminal connected to an external power supply terminal, its first output terminal connected to the first input terminal of a first amplifier, its second output terminal connected to the first input terminal of a second amplifier, its second input terminal connected to a MEMS backplate, its output terminal outputting a MEMS signal, its second input terminal connected to a piezoelectric sensor, and its output terminal outputting a piezoelectric signal.

[0059] In this embodiment, the bandgap reference source, charge pump, and LDO are power modulation modules. After the external power supply Vdd is input to the bandgap reference source, it outputs a voltage of 1.2V that is close to the silicon bandgap energy. This 1.2V voltage is then amplified by the charge pump through multiple stages and output to power the MEMS chip. After the external power supply Vdd is input to the LDO, it is stepped down and output to power the first amplifier and the second amplifier. The first amplifier amplifies the MEMS signal and outputs it at the Out1 output interface. The second amplifier amplifies the piezoelectric signal and outputs it at the Out2 output interface.

[0060] like Figure 3As shown, in one possible embodiment of this application, the bone conduction microphone further includes a processor, which includes a first analog gain module, a second analog gain module, a first analog-to-digital conversion module, a second analog-to-digital conversion module, a first digital gain module, a second digital gain module, a noise reduction chip, and a storage module.

[0061] The first analog gain module receives a MEMS signal at its input terminal. Its output terminal is connected to the input terminal of the first analog-to-digital converter module. The output terminal of the first analog-to-digital converter module is connected to the input terminal of the first digital gain module. The output terminal of the first digital gain module is connected to the first input terminal of the noise reduction chip. The second analog gain module receives a piezoelectric signal at its input terminal. Its output terminal is connected to the input terminal of the second analog-to-digital converter module. The output terminal of the second analog-to-digital converter module is connected to the input terminal of the second digital gain module. The output terminal of the second digital gain module is connected to the second input terminal of the noise reduction chip. The output terminal of the noise reduction chip is connected to the storage module.

[0062] In this embodiment, the MEMS signal and piezoelectric signal processed by the ASIC chip are amplified by the analog gain module and output to the analog-to-digital converter (ADC) module for analog-to-digital conversion. The digital signal is then amplified by the digital gain module to obtain signals x1(n) and x2(n) respectively. The MEMS signal and piezoelectric signal are then fused and filtered by the noise reduction chip to obtain the enhanced voice, which is then stored in the storage module.

[0063] like Figure 4 As shown, in one possible embodiment of this application, the noise reduction chip includes: a first noise reduction module and a second noise reduction module, wherein the output terminal of the first noise reduction module is connected to the input terminal of the second noise reduction module.

[0064] The first noise reduction module outputs a corresponding noise-reduced bone conduction speech signal to the second noise reduction module based on the size of the bone conduction speech signal and the speech signal threshold. The second noise reduction module then performs noise reduction processing on the noise-reduced bone conduction speech signal to obtain enhanced speech.

[0065] In other words, the noise reduction chip consists of two modules. The first module is a complementary Wiener filter module that fuses and filters MEMS and piezoelectric signals. The second module is a standard bone conduction microphone noise reduction module, which can use the spectral envelope method for noise reduction. The noise-reduced bone conduction speech signal output from the first module serves as the input to the target bone conduction speech in the second module. Specifically, as shown below.

[0066] like Figure 5As shown, when the bone-conducted voice signal is less than the voice signal threshold, the first noise reduction module includes: a first comparator, a first calculator, and a second comparator. The first input terminal of the first comparator is connected to the first digital gain module, the second input terminal of the first comparator is connected to the second digital gain module, the output terminal of the first comparator is connected to the input terminal of the first calculator, the output terminal of the first calculator is connected to the first input terminal of the second comparator, the second input terminal of the second comparator is connected to the first digital gain module, and the output terminal of the second comparator is connected to the second noise reduction module.

[0067] As Figure 6 shown, when the bone-conducted voice signal is greater than the voice signal threshold, the first noise reduction module includes: a third comparator, a second calculator, and a fourth comparator. The first input terminal of the third comparator is connected to the second digital gain module, the second input terminal of the third comparator is connected to the first digital gain module, the output terminal of the third comparator is connected to the input terminal of the second calculator, the output terminal of the second calculator is connected to the first input terminal of the fourth comparator, the second input terminal of the fourth comparator is connected to the second digital gain module, and the output terminal of the fourth comparator is connected to the second noise reduction module.

[0068] In the embodiment of the present application, let the MEMS signal be x1(n) = s(n) + v1(n), the piezoelectric element signal be x2(n) = s(n) + v2(n), s(n) be the pure bone-conducted signal, v(n) be the random noise signal, where the bone-conducted voice signal is the sum of the pure bone-conducted signal and the noise signal, and the voice signal threshold N is set. When the bone-conducted voice signal x < N, it is determined as a small vibration signal scenario. At this time, the piezoelectric sensor is more likely to recognize this tiny vibration. Therefore, the noise signal v(n) amplified together with s(n) after pre-amplification and digital gain is smaller, that is, v1(n) > v2(n). The pulse transfer function G(z) inputs y(n) = v1(n) - v2(n). At this time, v1(n) can be regarded as the new pure voice signal, v2(n) is the new noise signal, G(z) effectively filters v2(n) according to the least mean square error principle, and makes the best estimate of v1(n). The best impulse response vector is h opt = R -1 yy R yv1 (where R -1 yy is the inverse transform of the autocorrelation function of the input signal y(n) of G(z), and R yv1 is the cross-correlation function between y(n) and v1(n)), G(z) outputs v*1(n), and subtracting v*1(n) from the MEMS signal x1(n) = s(n) + v1(n) can obtain the noise-reduced bone-conducted voice signal in the small vibration scenario.

[0069] When the bone-conducted voice signal x > N, it is determined as a strong noise scenario. There is a lot of noise when the piezoelectric sensor processes strong vibration sound waves. Therefore, after pre-amplification (both analog and digital), the noise signal v(n) amplified together with s(n) is larger, that is, v2(n) > v1(n). The input of G(z) is y(n) = v2(n) - v1(n), and the optimal impulse response vector is h opt = R -1 yy R yv2 , and the output is v*2(n). Subtracting v*2(n) from the piezoelectric signal x2(n) = s(n) + v2(n), the noise-reduced bone-conducted voice signal in the strong noise scenario can be obtained.

[0070] It should be noted that x is the MEMS signal and the piezoelectric signal. That is to say, x < N means that both the MEMS signal and the piezoelectric signal are less than N, and x > N means that both the MEMS signal and the piezoelectric signal are greater than N.

[0071] As Figure 7 shown, it is the structural block diagram of the second noise reduction module, as shown below. Specifically, this embodiment will not be described in detail.

[0072] The spectral envelope method is based on the source-filter model of speech. This model regards speech as being obtained by modulating a sound excitation signal (source) through the vocal tract (filter), and is usually represented by spectral envelope features. Since bone-conducted speech and air-conducted speech come from the same sound source and the excitation signals are approximately the same, the air-conducted speech signal can be obtained by only converting the spectral envelope features, thus realizing speech enhancement. The common expression for solving the spectral envelope is:

[0073]

[0074] where, x n (t) is the speech signal, LPF is the low-pass filter, j is the imaginary number, and Hilbert(x n (t)) is the Hilbert transform of the speech signal x n (t).

[0075] The embodiment of the present application also provides a noise reduction method. As Figure 8 shown, this noise reduction method is applied to the bone conduction microphone provided in any of the above embodiments, and this noise reduction method may include the steps shown in S801 to S806.

[0076] In S801, the MEMS signal and the piezoelectric signal are obtained.

[0077] Among them, the MEMS signal is the signal output by the MEMS chip after being processed by the application-specific integrated circuit chip, and the piezoelectric signal is the signal output by the piezoelectric sensor after being processed by the application-specific integrated circuit chip.

[0078] In S802, when both the microelectromechanical system signal and the piezoelectric signal are less than the threshold of the voice signal, the first difference between the microelectromechanical system signal and the piezoelectric signal is obtained.

[0079] The voice signal threshold is a set value, which can be set based on experience or actual application. This application does not limit the specific value.

[0080] In S803, the first noise-reduced bone conduction speech signal is obtained based on the first difference.

[0081] In S804, when both the microelectromechanical system signal and the piezoelectric signal are greater than the speech signal threshold, a second difference between the piezoelectric signal and the microelectromechanical system signal is obtained.

[0082] In S805, the second noise-reduced bone conduction speech signal is obtained based on the second difference.

[0083] In S806, the first or second noise-reduced bone conduction speech signal is subjected to noise reduction processing to obtain enhanced speech.

[0084] In this embodiment, firstly, the MEMS signal (processed by an ASIC chip) outputting the MEMS chip and the piezoelectric signal (processed by an ASIC chip) outputting the piezoelectric sensor are obtained. Then, when both the MEMS signal and the piezoelectric signal are less than the speech signal threshold, a first difference between the MEMS signal and the piezoelectric signal is obtained. Based on this first difference, a first noise-reduced bone conduction speech signal is obtained. When both the MEMS signal and the piezoelectric signal are greater than the speech signal threshold, a second difference between the piezoelectric signal and the MEMS signal is obtained. Based on this second difference, a second noise-reduced bone conduction speech signal is obtained. Finally, noise reduction processing is performed on either the first or second noise-reduced bone conduction speech signal to obtain enhanced speech. This embodiment uses MEMS and piezoelectric signal fusion filtering and sets a speech signal threshold to identify different noise reduction scenarios. It is applicable to low-vibration scenarios and high-noise scenarios to improve the noise reduction capability of bone conduction microphones.

[0085] It should be noted that the noise reduction method provided in this application embodiment can be executed by a noise reduction device or a control module in the noise reduction device for executing the noise reduction method. This application embodiment uses the noise reduction device executing the noise reduction method as an example to illustrate the noise reduction device provided in this application embodiment.

[0086] like Figure 9As shown, this application embodiment also provides a noise reduction device, which is applied to the bone conduction microphone provided in any of the above embodiments. The noise reduction device may include: a first acquisition module 901, a second acquisition module 902, a first determination module 903, a third acquisition module 904, a second determination module 905, and a noise reduction module 906.

[0087] The system comprises the following modules: a first acquisition module 901, used to acquire a microelectromechanical system (MEMS) signal and a piezoelectric signal, wherein the MEMS signal is the signal output by the MEMS chip processed by a dedicated integrated circuit (DAC) chip, and the piezoelectric signal is the signal output by the piezoelectric sensor processed by a DAC chip; a second acquisition module 902, used to acquire a first difference between the MEMS signal and the piezoelectric signal when both the MEMS signal and the piezoelectric signal are less than a speech signal threshold; a first determination module 903, used to obtain a first noise-reduced bone conduction speech signal based on the first difference; a third acquisition module 904, used to acquire a second difference between the piezoelectric signal and the MEMS signal when both the MEMS signal and the piezoelectric signal are greater than a speech signal threshold; a second determination module 905, used to obtain a second noise-reduced bone conduction speech signal based on the second difference; and a noise reduction module 906, used to perform noise reduction processing on either the first or second noise-reduced bone conduction speech signal to obtain enhanced speech.

[0088] In this embodiment, the first acquisition module 901 first acquires the MEMS signal (processed by the ASIC chip) from the signal output by the MEMS chip and the piezoelectric signal (processed by the ASIC chip) from the signal output by the piezoelectric sensor. Then, the second acquisition module 902, when both the MEMS signal and the piezoelectric signal are less than the speech signal threshold, acquires the first difference between the MEMS signal and the piezoelectric signal. The first determination module 903 obtains the first noise-reduced bone conduction speech signal based on the first difference. The third acquisition module 904, when both the MEMS signal and the piezoelectric signal are greater than the speech signal threshold, acquires the second difference between the piezoelectric signal and the MEMS signal. The second determination module 905 obtains the second noise-reduced bone conduction speech signal based on the second difference. Finally, the noise reduction module 906 performs noise reduction processing on either the first or second noise-reduced bone conduction speech signal to obtain enhanced speech. This embodiment uses MEMS and piezoelectric signal fusion filtering and sets a speech signal threshold to identify different noise reduction scenarios, making it applicable to low-vibration scenarios and high-noise scenarios, thereby improving the noise reduction capability of the bone conduction microphone.

[0089] The noise reduction device in the embodiments of this application can be a device, or it can be a component, integrated circuit, or chip in a terminal.

[0090] The noise reduction device in this application embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this application embodiment does not specifically limit it.

[0091] The noise reduction device provided in this application embodiment can achieve Figure 8 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0092] Optional, such as Figure 10 As shown, this application embodiment also provides a bone conduction microphone 1000, including a processor 1001, a memory 1002, and a program or instructions stored in the memory 1002 and executable on the processor 1001. When the program or instructions are executed by the processor 1001, they implement the various processes of the above-described noise reduction method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0093] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the noise reduction method embodiments provided in any of the above embodiments. Furthermore, they achieve the same technical effects, and to avoid repetition, they will not be described again here.

[0094] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0095] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described noise reduction method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0096] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0097] This application also provides a computer program product stored in a non-transient storage medium. When the computer program product is executed by the processor, it implements the various processes of the above-described noise reduction method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0098] This application also provides a processing device, which is configured to execute the various processes of the above-described noise reduction method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0099] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0100] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0101] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A bone conduction microphone, characterized in that, include: Housing, piezoelectric sensor, vibration component, circuit board, microelectromechanical system chip, application-specific integrated circuit chip and processor, The housing is connected to the circuit board to form a first cavity. The vibrating element, the microelectromechanical system chip, and the dedicated integrated circuit chip are all disposed in the first cavity. The microelectromechanical system chip and the dedicated integrated circuit chip are both electrically connected to the circuit board. The microelectromechanical system chip and the dedicated integrated circuit chip are electrically connected. The piezoelectric sensor is disposed on the side of the housing facing the first cavity, and the piezoelectric sensor is electrically connected to the circuit board; The processor includes a first analog gain module, a second analog gain module, a first analog-to-digital conversion module, a second analog-to-digital conversion module, a first digital gain module, a second digital gain module, a noise reduction chip, and a storage module; The first analog gain module receives a microelectromechanical system (MEMS) signal at its input terminal. Its output terminal is connected to the input terminal of the first analog-to-digital converter (ADC). The output terminal of the first ADC is connected to the input terminal of the first digital gain module. The output terminal of the first digital gain module is connected to the first input terminal of the noise reduction chip. The second analog gain module receives a piezoelectric signal at its input terminal. Its output terminal is connected to the input terminal of the second ADC. The output terminal of the second ADC is connected to the input terminal of the second digital gain module. The output terminal of the second digital gain module is connected to the second input terminal of the noise reduction chip. The output terminal of the noise reduction chip is connected to the storage module. The MEMS signal is the signal output by the MEMS chip after processing by the dedicated integrated circuit (DAC) chip. The piezoelectric signal is the signal output by the piezoelectric sensor after processing by the DAC chip.

2. The bone conduction microphone according to claim 1, characterized in that, The circuit board includes a first board, a second board, a third board, and a fourth board. The first board, the second board, the third board, and the fourth board form a second cavity. The first board and the second board are disposed opposite each other. The first board is disposed on the side of the second board away from the housing. A first hole is provided on the second board. The microelectromechanical system (MEMS) chip and the application-specific integrated circuit (ASIC) chip are both disposed on the side of the second board facing the first board, and the MEMS chip is disposed facing the first hole. The vibrating element is disposed on the side of the second board facing the housing, and the vibrating element is disposed facing the first hole.

3. The bone conduction microphone according to claim 2, characterized in that, The vibrating element includes a mass block and an elastic diaphragm. The elastic diaphragm is mounted on the second plate by a support member, and the mass block is located on the side of the elastic diaphragm away from the second plate.

4. The bone conduction microphone according to claim 2, characterized in that, The piezoelectric sensor is electrically connected to the second plate via a wire.

5. The bone conduction microphone according to claim 2, characterized in that, The microelectromechanical system (MEMS) chip includes a MEMS backplate and a MEMS diaphragm. The MEMS backplate includes a first MEMS backplate and a second MEMS backplate, which are respectively disposed on both sides of the first hole. The MEMS diaphragm is electrically connected to the second plate body through the first MEMS backplate and the second MEMS backplate.

6. The bone conduction microphone according to claim 5, characterized in that, The application-specific integrated circuit chip includes a charge pump, a bandgap reference source, a first amplifier, a second amplifier, and a low-dropout linear regulator; The input terminal of the bandgap reference source is connected to an external power supply terminal, the output terminal of the bandgap reference source is connected to the input terminal of the charge pump, the output terminal of the charge pump is connected to the diaphragm of the microelectromechanical system (MEMS), and the external power supply terminal is used to power the MEMS chip. The input terminal of the low-dropout linear regulator is connected to the external power supply terminal. The first output terminal of the low-dropout linear regulator is connected to the first input terminal of the first amplifier. The second output terminal of the low-dropout linear regulator is connected to the first input terminal of the second amplifier. The second input terminal of the first amplifier is connected to the back electrode plate of the microelectromechanical system (MEMS). The output terminal of the first amplifier outputs a MEMS signal. The second input terminal of the second amplifier is connected to the piezoelectric sensor. The output terminal of the second amplifier outputs a piezoelectric signal.

7. The bone conduction microphone according to claim 1, characterized in that, The noise reduction chip includes: a first noise reduction module and a second noise reduction module, wherein the output terminal of the first noise reduction module is connected to the input terminal of the second noise reduction module; The first noise reduction module outputs a corresponding noise-reduced bone conduction speech signal to the second noise reduction module based on the magnitude of the bone conduction speech signal and the speech signal threshold. The second noise reduction module performs noise reduction processing on the noise-reduced bone conduction speech signal to obtain enhanced speech. The bone conduction speech signal includes microelectromechanical system signals and piezoelectric signals. When both the microelectromechanical system signal and the piezoelectric signal are less than the speech signal threshold, the first noise reduction module includes: a first comparator, a first calculator, and a second comparator. The first input terminal of the first comparator is connected to the first digital gain module, the second input terminal of the first comparator is connected to the second digital gain module, the output terminal of the first comparator is connected to the input terminal of the first calculator, the output terminal of the first calculator is connected to the first input terminal of the second comparator, the second input terminal of the second comparator is connected to the first digital gain module, and the output terminal of the second comparator is connected to the second noise reduction module. When both the microelectromechanical system signal and the piezoelectric signal are greater than the speech signal threshold, the first noise reduction module includes: a third comparator, a second comparator, and a fourth comparator. The first input terminal of the third comparator is connected to the second digital gain module, the second input terminal of the third comparator is connected to the first digital gain module, the output terminal of the third comparator is connected to the input terminal of the second calculator, the output terminal of the second calculator is connected to the first input terminal of the fourth comparator, the second input terminal of the fourth comparator is connected to the second digital gain module, and the output terminal of the fourth comparator is connected to the second noise reduction module.

8. A noise reduction method, characterized in that, The noise reduction method, applied to the bone conduction microphone according to any one of claims 1-7, comprises: Acquire microelectromechanical system (MEMS) signals and piezoelectric signals, wherein the MEMS signals are signals output by the MEMS chip and processed by a dedicated integrated circuit (DAC) chip, and the piezoelectric signals are signals output by the piezoelectric sensor and processed by the DAC chip; When both the microelectromechanical system signal and the piezoelectric signal are less than the speech signal threshold, a first difference between the microelectromechanical system signal and the piezoelectric signal is obtained. Based on the first difference, the first noise-reduced bone conduction speech signal is obtained; When both the microelectromechanical system signal and the piezoelectric signal are greater than the speech signal threshold, a second difference between the piezoelectric signal and the microelectromechanical system signal is obtained; Based on the second difference, the second noise-reduced bone conduction speech signal is obtained; The first or second noise-reduced bone conduction speech signal is subjected to noise reduction processing to obtain enhanced speech.

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