Audio signal optimization circuit with voice acquisition

Abstract

The utility model discloses a kind of audio signal optimization circuit with voice collection, including main signal path and feedback signal path, main signal path includes main microphone input interface, main preamplification and filter circuit, main analog-to-digital converter ADC, main digital signal processor DSP, digital-to-analog converter DAC, power amplification circuit and loudspeaker output, main microphone input interface, main preamplification and filter circuit, main analog-to-digital converter ADC, main digital signal processor DSP, digital-to-analog converter DAC, power amplification circuit and loudspeaker output are sequentially connected.The utility model adds feedback microphone and symmetrical signal conditioning and digitizing circuit in loudspeaker end, and this road signal is merged into main digital signal processor DSP, and the real-time, accurate monitoring of final acoustic output effect of system is realized from hardware level.

Description

Technical Field

[0001] This utility model relates to the field of audio signal optimization circuit technology, and in particular to an audio signal optimization circuit with voice acquisition. Background Technology

[0002] Existing audio signal optimization circuits mostly employ an open-loop processing mode, where the signal is input from the microphone, processed, and then output from the speaker. These existing circuits suffer from the following shortcomings: 1. The circuit cannot determine the actual acoustic effect after output to the speaker, nor the impact of the environment on the sound; 2. Due to the inherent tolerances, aging drift, and temperature drift of analog components (such as operational amplifiers, capacitors, and resistors), the circuit's processing accuracy decreases over time and with environmental changes, and it cannot be automatically calibrated, leading to increased distortion and deteriorated sound quality. In light of these factors, this application proposes an audio signal optimization circuit with voice acquisition capabilities. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing an audio signal optimization circuit with voice acquisition.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An audio signal optimization circuit with voice acquisition includes a main signal path and a feedback signal path. The main signal path includes a main microphone input interface, a main preamplifier and filter circuit, a main analog-to-digital converter (ADC), a main digital signal processor (DSP), a digital-to-analog converter (DAC), a power amplifier circuit, and a speaker output port. The main microphone input interface, the main preamplifier and filter circuit, the main analog-to-digital converter (ADC), the main digital signal processor (DSP), the digital-to-analog converter (DAC), the power amplifier circuit, and the speaker output port are connected in sequence.

[0006] The feedback signal path includes a feedback microphone input interface, a feedback preamplifier and filter circuit, a feedback analog-to-digital converter (ADC), and a feedback digital signal processor (DSP), which are connected in sequence.

[0007] Preferably, the main preamplifier and filter circuit includes operational amplifier U1 and operational amplifier U2. Pin 1 of operational amplifier U1 is electrically connected to one end of resistor R1, and pin 2 of operational amplifier U1 is electrically connected to one end of capacitor C1. Pin 1 of operational amplifier U2 is electrically connected to one end of resistor R2, and pin 2 of operational amplifier U2 is electrically connected to one end of capacitor C2. The other end of capacitor C1 is electrically connected to the other end of resistor R2, the other end of resistor R1 is electrically connected to the other end of capacitor C2, the other end of capacitor C2 is electrically connected to one end of resistor R6, the other end of resistor R6 is electrically connected to one end of resistor R7, and the other end of resistor R7 is electrically connected to one end of resistor R8. Pin 3 of operational amplifier U1 and... Pin 3 of operational amplifier U2 is electrically connected to one end of resistor R4 and one end of resistor R5, respectively. Pin 3 of operational amplifier U1 and pin 3 of operational amplifier U2 are connected in series with resistor R3. The other ends of resistor R4 and resistor R5 are electrically connected to one end of capacitor C4 and one end of capacitor C3, respectively. The other ends of capacitor C4 and capacitor C3 are electrically connected to the same resistor R9. The other end of resistor R9 is grounded. The other end of resistor R8 is electrically connected to one end of resistor R9. The other ends of resistor R1, capacitor C2, and resistor R6 are all electrically connected to the main microphone input interface. The other ends of resistor R2 and capacitor C1 are all electrically connected to the analog input pin of the main analog-to-digital converter (ADC).

[0008] Preferably, the power amplifier circuit includes an operational amplifier U3. Pin 1 of the operational amplifier U3 is electrically connected to one end of a resistor R10. The other end of the resistor R10 is electrically connected to one end of a capacitor C5 and one end of a resistor R13. Pin 2 of the operational amplifier U3 is electrically connected to one end of a resistor R11. Pin 5 of the operational amplifier U3 is electrically connected to one end of a capacitor C6. The other ends of capacitor C6, resistor R11, and capacitor C5 are electrically connected to the same resistor R12. Pin 3 of the operational amplifier U3 is electrically connected to one end of a capacitor C7. The other ends of resistor R13 and resistor R12 are both electrically connected to the other end of capacitor C7. Pin 4 of the operational amplifier U3 is electrically connected to the output pin of the digital-to-analog converter (DAC). The other end of capacitor C7 is electrically connected to the speaker output port.

[0009] Preferably, the feedback preamplifier and filter circuit includes an operational amplifier U4. Pin 1 of the operational amplifier U4 is electrically connected to one end of a resistor R15. Pin 2 of the operational amplifier U4 is electrically connected to one end of a capacitor C8. The other end of the capacitor C8 is electrically connected to the feedback microphone input interface. The other end of the resistor R15 is electrically connected to one end of a capacitor C11. Pin 3 of the operational amplifier U4 is electrically connected to one end of a resistor R14. The other end of the resistor R14 is electrically connected to one end of a capacitor C10. Pin 4 of the operational amplifier U4 is electrically connected to one end of a capacitor C9. The other end of the capacitor C9 is electrically connected to one end of a resistor R16. The other end of the resistor R16 is electrically connected to the other end of the resistor R15 and one end of the capacitor C11. The other ends of the capacitors C10, C9, and C11 are all electrically connected to the input pin of the feedback analog-to-digital converter (ADC).

[0010] Preferably, the main digital signal processor (DSP) and the feedback digital signal processor (DSP) are integrated on the same physical chip to form a multi-core digital signal processor. The multi-core digital signal processor has a first digital signal input port, a second digital signal input port, and a digital signal output port. The digital output terminal of the main analog-to-digital converter (ADC) is connected to the first digital signal input port, the digital output terminal of the feedback analog-to-digital converter (ADC) is connected to the second digital signal input port, and the digital signal output port is connected to the digital input terminal of the digital-to-analog converter (DAC).

[0011] Preferably, the main digital signal processor (DSP) and the feedback digital signal processor (DSP) are the same digital signal processor. The digital signal processor is provided with a first signal input interface and a second signal input interface. The output terminal of the main analog-to-digital converter (ADC) is connected to the first signal input interface of the digital signal processor, and the output terminal of the feedback analog-to-digital converter (ADC) is connected to the second signal input interface of the digital signal processor.

[0012] Preferably, the signal output terminal of the feedback digital signal processor (DSP) is connected to the control terminal of the main digital signal processor (DSP), and the main DSP is configured to operate according to the signal output by the feedback DSP.

[0013] Compared with existing technologies, the beneficial effects of this utility model are:

[0014] This invention adds a feedback microphone and symmetrical signal conditioning and digitization circuits to the speaker end, and feeds the signal into the main digital signal processor (DSP). This enables real-time and accurate monitoring of the final acoustic output effect of the system at the hardware level. It can also automatically identify and dynamically compensate for frequency response distortion and nonlinear distortion caused by the tolerance of analog components, temperature drift, speaker nonlinear characteristics and complex room acoustic environment, thereby effectively improving the accuracy and fidelity of audio playback. Attached Figure Description

[0015] Figure 1 This invention provides a system block diagram of an audio signal optimization circuit with voice acquisition.

[0016] Figure 2 The diagram shows the main preamplifier and filter circuit in an audio signal optimization circuit with voice acquisition proposed in this utility model.

[0017] Figure 3 The diagram shows the power amplifier circuit in an audio signal optimization circuit with voice acquisition proposed in this utility model.

[0018] Figure 4 The diagram shows the feedback preamplifier and filter circuit in an audio signal optimization circuit with voice acquisition proposed in this utility model. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0020] Reference Figure 1-4 An audio signal optimization circuit with voice acquisition includes a main signal path and a feedback signal path. The main signal path includes a main microphone input interface, a main preamplifier and filter circuit, a main analog-to-digital converter (ADC), a main digital signal processor (DSP), a digital-to-analog converter (DAC), a power amplifier circuit, and a speaker output port. The main microphone input interface, the main preamplifier and filter circuit, the main analog-to-digital converter (ADC), the main digital signal processor (DSP), the digital-to-analog converter (DAC), the power amplifier circuit, and the speaker output port are connected in sequence.

[0021] The main preamplifier and filter circuit includes operational amplifiers U1 and U2. Pin 1 of operational amplifier U1 is electrically connected to one end of resistor R1, and pin 2 of operational amplifier U1 is electrically connected to one end of capacitor C1. Pin 1 of operational amplifier U2 is electrically connected to one end of resistor R2, and pin 2 of operational amplifier U2 is electrically connected to one end of capacitor C2. The other end of capacitor C1 is electrically connected to the other end of resistor R2, the other end of resistor R1 is electrically connected to the other end of capacitor C2, the other end of capacitor C2 is electrically connected to one end of resistor R6, the other end of resistor R6 is electrically connected to one end of resistor R7, and the other end of resistor R7 is electrically connected to one end of resistor R8. Pin 3 of operational amplifier U1 and operational amplifier U2 are connected to the other end of the filter circuit. Pin 3 of amplifier U2 is electrically connected to one end of resistor R4 and one end of resistor R5 respectively. Pin 3 of operational amplifier U1 and pin 3 of operational amplifier U2 are connected in series with resistor R3. The other ends of resistor R4 and resistor R5 are electrically connected to one end of capacitor C4 and one end of capacitor C3 respectively. The other ends of capacitor C4 and capacitor C3 are electrically connected to the same resistor R9. The other end of resistor R9 is grounded. The other end of resistor R8 is electrically connected to one end of resistor R9. The other ends of resistor R1, capacitor C2 and resistor R6 are all electrically connected to the main microphone input interface. The other ends of resistor R2 and capacitor C1 are all electrically connected to the analog input pin of the main analog-to-digital converter (ADC).

[0022] The operation of the main preamplifier and filter circuit begins with the input of a weak microphone signal. The signal first passes through a high-pass network composed of capacitor C1 and resistor R1 to filter out low-frequency noise. Then, it enters the preamplifier stage composed of operational amplifier U1 and its peripheral resistors R3 and R4 for amplitude boosting. The amplified signal is then subjected to deep negative feedback and shunting of high-frequency components by a multi-path feedback second-order low-pass filter composed of resistors R5, R8, R9, capacitors C3 and C4 to effectively filter out out-of-band high-frequency noise and potential aliasing noise. Finally, the clean analog signal, after this high-pass amplification and low-pass filtering process, is output to the main analog-to-digital converter (ADC), completing all analog domain signal conditioning from acquisition to digitization.

[0023] The power amplifier circuit includes operational amplifier U3. Pin 1 of operational amplifier U3 is electrically connected to one end of resistor R10. The other end of resistor R10 is electrically connected to one end of capacitor C5 and one end of resistor R13. Pin 2 of operational amplifier U3 is electrically connected to one end of resistor R11. Pin 5 of operational amplifier U3 is electrically connected to one end of capacitor C6. The other end of capacitor C6, the other end of resistor R11, and the other end of capacitor C5 are electrically connected to the same resistor R12. Pin 3 of operational amplifier U3 is electrically connected to one end of capacitor C7. The other ends of resistor R13 and resistor R12 are both electrically connected to the other end of capacitor C7. Pin 4 of operational amplifier U3 is electrically connected to the output pin of digital-to-analog converter (DAC). The other end of capacitor C7 is electrically connected to the speaker output port.

[0024] The operation of this power amplifier circuit begins with the analog audio signal output from the digital-to-analog converter (ADC) being input to the operational amplifier U3. The feedback network consisting of the operational amplifier U3 and its surrounding resistors and capacitors precisely amplifies the voltage and enhances the current driving capability of the signal. After the amplified signal passes through the output coupling capacitor to filter out harmful DC components, the pure AC audio power signal is delivered to the speaker interface, ultimately driving the speaker voice coil to generate corresponding mechanical vibration, thereby reproducing high-fidelity sound.

[0025] The feedback signal path includes a feedback microphone input interface, a feedback preamplifier and filter circuit, a feedback analog-to-digital converter (ADC), and a feedback digital signal processor (DSP). The feedback microphone input interface, the feedback preamplifier and filter circuit, the feedback analog-to-digital converter (ADC), and the feedback digital signal processor (DSP) are connected in sequence.

[0026] The feedback preamplifier and filter circuit includes operational amplifier U4. Pin 1 of operational amplifier U4 is electrically connected to one end of resistor R15. Pin 2 of operational amplifier U4 is electrically connected to one end of capacitor C8. The other end of capacitor C8 is electrically connected to the feedback microphone input interface. The other end of resistor R15 is electrically connected to one end of capacitor C11. Pin 3 of operational amplifier U4 is electrically connected to one end of resistor R14. The other end of resistor R14 is electrically connected to one end of capacitor C10. Pin 4 of operational amplifier U4 is electrically connected to one end of capacitor C9. The other end of capacitor C9 is electrically connected to one end of resistor R16. The other end of resistor R16 is electrically connected to the other end of resistor R15 and one end of capacitor C11. The other ends of capacitors C10, C9, and C11 are all electrically connected to the input pin of the feedback analog-to-digital converter (ADC).

[0027] The main digital signal processor (DSP) and the feedback digital signal processor (DSP) are integrated on the same physical chip to form a multi-core digital signal processor. The multi-core digital signal processor has a first digital signal input port, a second digital signal input port, and a digital signal output port. The digital output terminal of the main analog-to-digital converter (ADC) is connected to the first digital signal input port, the digital output terminal of the feedback analog-to-digital converter (ADC) is connected to the second digital signal input port, and the digital signal output port is connected to the digital input terminal of the digital-to-analog converter (DAC).

[0028] The main digital signal processor (DSP) and the feedback digital signal processor (DSP) are the same digital signal processor. The digital signal processor is provided with a first signal input interface and a second signal input interface. The output of the main analog-to-digital converter (ADC) is connected to the first signal input interface of the digital signal processor, and the output of the feedback analog-to-digital converter (ADC) is connected to the second signal input interface of the digital signal processor.

[0029] The main digital signal processor (DSP) and the feedback digital signal processor (DSP) are the same digital signal processor. The digital signal processor is provided with a first signal input interface and a second signal input interface. The output of the main analog-to-digital converter (ADC) is connected to the first signal input interface of the digital signal processor, and the output of the feedback analog-to-digital converter (ADC) is connected to the second signal input interface of the digital signal processor.

[0030] The feedback preamplifier and filter circuit achieves high-precision conditioning of the feedback microphone signal through the coordinated operation of operational amplifier U4 and a resistor-capacitor network. It uses capacitor C8 to achieve AC coupling of the input signal to filter out DC bias, and uses operational amplifier U4 and external resistor network to form an amplification circuit to stabilize the gain of weak signals. The filter network composed of capacitors C9, C10, C11 and other components effectively suppresses high-frequency noise and aliasing interference. Finally, the pure signal after amplification and filtering is sent to the feedback analog-to-digital converter (ADC), providing an accurate and reliable feedback signal source for the subsequent digital signal processing system. The digital signal output by the feedback ADC is sent to the input port of the feedback digital signal processor (DSP). The feedback DSP sends its signal to the main DSP, which dynamically adjusts its internal hardware register parameters accordingly, thereby changing the processing intensity of the main path signal. This ensures that the entire audio optimization circuit can perform precise closed-loop adjustment based on the real acoustic output.

[0031] It should be noted that when the main digital signal processor (DSP) adjusts its internal hardware register parameters, it receives system status parameters from the feedback DSP, compares them with the internally stored parameter mapping table, calculates the required correction amount, and writes the new configuration value into the hardware control registers of processing units such as equalizers and filters via the internal bus. This directly changes the internal circuit structure of these units and the intensity of signal processing, thereby achieving adaptive adjustment of audio characteristics. The main DSP can preferably be the Texas Instruments TMS320C5000 series digital signal processor. The specific principle is existing technology and will not be elaborated here.

[0032] This invention adds a feedback microphone and symmetrical signal conditioning and digitization circuits to the speaker end, and feeds the signal into the main digital signal processor (DSP). This enables real-time and accurate monitoring of the final acoustic output effect of the system at the hardware level. It can also automatically identify and dynamically compensate for frequency response distortion and nonlinear distortion caused by the tolerance of analog components, temperature drift, speaker nonlinear characteristics and complex room acoustic environment, thereby effectively improving the accuracy and fidelity of audio playback.

[0033] Working Principle: The acoustic signal of the target sound source is captured by the main microphone and enters the circuit through the main microphone input interface, where it is converted into a weak electrical signal. This weak signal then enters the main preamplifier and filter circuit. Operational amplifiers U1 and U2 in the main preamplifier and filter circuit work together to amplify the millivolt-level signal to the volt level to meet the input requirements of subsequent circuits. The signal is then filtered by a filter network composed of capacitors and resistors in this circuit, removing extremely low-frequency noise and high-frequency interference. The conditioned, clean analog signal is sent to the main analog-to-digital converter (ADC). The ADC reads the analog signal at fixed time intervals. The voltage is converted into a series of digital codes. The digital signal enters the main digital signal processor (DSP), which receives the digital signal from the main analog-to-digital converter (ADC) through its first signal input interface. After processing the received signal, it is sent out from its output port. The digital signal output by the main DSP is received by the digital-to-analog converter (DAC). The DAC reconstructs the digital code into an analog waveform. The reconstructed analog signal enters the power amplifier circuit to boost the voltage and current of the signal, giving it sufficient energy. The high-power analog signal drives the speaker through the speaker output port, restoring the electrical signal into a sound wave.

[0034] Meanwhile, a feedback microphone is placed near the speaker to collect the final sound emitted by the speaker after interacting with the room environment. This sound enters the circuit through the feedback microphone input interface. The collected signal enters the feedback preamplifier and filter circuit for amplification and filtering. The conditioned feedback analog signal is sampled and quantized by the feedback analog-to-digital converter (ADC) and converted into a digital signal. The digital signal output by the feedback ADC is sent to the input port of the feedback digital signal processor (DSP). At this time, there are two digital signals inside both the main DSP and the feedback DSP: one is the original input signal of "expected playback" (from the main path), and the other is the monitoring signal of "actual playback effect" (from the feedback path). The feedback DSP sends its signal to the main DSP, which dynamically adjusts its internal hardware register parameters accordingly, thereby changing the processing intensity of the main path signal, forming a real-time hardware closed loop of "output-acquisition-comparison-adjustment-re-output", ultimately realizing automatic compensation and optimization of the frequency response and distortion of the entire system.

[0035] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An audio signal optimization circuit with voice acquisition, characterized in that, It includes a main signal path and a feedback signal path. The main signal path includes a main microphone input interface, a main preamplifier and filter circuit, a main analog-to-digital converter (ADC), a main digital signal processor (DSP), a digital-to-analog converter (DAC), a power amplifier circuit, and a speaker output port. The main microphone input interface, the main preamplifier and filter circuit, the main analog-to-digital converter (ADC), the main digital signal processor (DSP), the digital-to-analog converter (DAC), the power amplifier circuit, and the speaker output port are connected in sequence. The feedback signal path includes a feedback microphone input interface, a feedback preamplifier and filter circuit, a feedback analog-to-digital converter (ADC), and a feedback digital signal processor (DSP), which are connected in sequence.

2. The audio signal optimization circuit with voice acquisition according to claim 1, characterized in that, The main preamplifier and filter circuit includes operational amplifier U1 and operational amplifier U2. Pin 1 of operational amplifier U1 is electrically connected to one end of resistor R1, and pin 2 of operational amplifier U1 is electrically connected to one end of capacitor C1. Pin 1 of operational amplifier U2 is electrically connected to one end of resistor R2, and pin 2 of operational amplifier U2 is electrically connected to one end of capacitor C2. The other end of capacitor C1 is electrically connected to the other end of resistor R2, the other end of resistor R1 is electrically connected to the other end of capacitor C2, the other end of capacitor C2 is electrically connected to one end of resistor R6, the other end of resistor R6 is electrically connected to one end of resistor R7, and the other end of resistor R7 is electrically connected to one end of resistor R8. Pin 3 of operational amplifier U1 and operational amplifier U2 are electrically connected to one end of resistor R1, and pin 2 of operational amplifier U2 is electrically connected to one end of resistor R2. Pin 3 of amplifier U2 is electrically connected to one end of resistor R4 and one end of resistor R5, respectively. Pin 3 of operational amplifier U1 and pin 3 of operational amplifier U2 are connected in series with resistor R3. The other ends of resistor R4 and resistor R5 are electrically connected to one end of capacitor C4 and one end of capacitor C3, respectively. The other ends of capacitor C4 and capacitor C3 are electrically connected to the same resistor R9. The other end of resistor R9 is grounded. The other end of resistor R8 is electrically connected to one end of resistor R9. The other ends of resistor R1, capacitor C2, and resistor R6 are all electrically connected to the main microphone input interface. The other ends of resistor R2 and capacitor C1 are all electrically connected to the analog input pin of the main analog-to-digital converter (ADC).

3. The audio signal optimization circuit with voice acquisition according to claim 1, characterized in that, The power amplifier circuit includes an operational amplifier U3. Pin 1 of the operational amplifier U3 is electrically connected to one end of a resistor R10. The other end of the resistor R10 is electrically connected to one end of a capacitor C5 and one end of a resistor R13. Pin 2 of the operational amplifier U3 is electrically connected to one end of a resistor R11. Pin 5 of the operational amplifier U3 is electrically connected to one end of a capacitor C6. The other ends of capacitor C6, resistor R11, and capacitor C5 are electrically connected to the same resistor R12. Pin 3 of the operational amplifier U3 is electrically connected to one end of a capacitor C7. The other ends of resistor R13 and resistor R12 are both electrically connected to the other end of capacitor C7. Pin 4 of the operational amplifier U3 is electrically connected to the output pin of the digital-to-analog converter (DAC). The other end of capacitor C7 is electrically connected to the speaker output port.

4. The audio signal optimization circuit with voice acquisition according to claim 1, characterized in that, The feedback preamplifier and filter circuit includes an operational amplifier U4. Pin 1 of the operational amplifier U4 is electrically connected to one end of a resistor R15. Pin 2 of the operational amplifier U4 is electrically connected to one end of a capacitor C8. The other end of the capacitor C8 is electrically connected to the feedback microphone input interface. The other end of the resistor R15 is electrically connected to one end of a capacitor C11. Pin 3 of the operational amplifier U4 is electrically connected to one end of a resistor R14. The other end of the resistor R14 is electrically connected to one end of a capacitor C10. Pin 4 of the operational amplifier U4 is electrically connected to one end of a capacitor C9. The other end of the capacitor C9 is electrically connected to one end of a resistor R16. The other end of the resistor R16 is electrically connected to the other end of the resistor R15 and one end of the capacitor C11. The other ends of the capacitors C10, C9, and C11 are all electrically connected to the input pin of the feedback analog-to-digital converter (ADC).

5. The audio signal optimization circuit with voice acquisition according to claim 1, characterized in that, The main digital signal processor (DSP) and the feedback digital signal processor (DSP) are integrated on the same physical chip to form a multi-core digital signal processor. The multi-core digital signal processor has a first digital signal input port, a second digital signal input port, and a digital signal output port. The digital output terminal of the main analog-to-digital converter (ADC) is connected to the first digital signal input port, the digital output terminal of the feedback analog-to-digital converter (ADC) is connected to the second digital signal input port, and the digital signal output port is connected to the digital input terminal of the digital-to-analog converter (DAC).

6. The audio signal optimization circuit with voice acquisition according to claim 1, characterized in that, The main digital signal processor (DSP) and the feedback digital signal processor (DSP) are the same digital signal processor. The digital signal processor is provided with a first signal input interface and a second signal input interface. The output terminal of the main analog-to-digital converter (ADC) is connected to the first signal input interface of the digital signal processor, and the output terminal of the feedback analog-to-digital converter (ADC) is connected to the second signal input interface of the digital signal processor.

7. The audio signal optimization circuit with voice acquisition according to claim 6, characterized in that, The signal output terminal of the feedback digital signal processor (DSP) is connected to the control terminal of the main digital signal processor (DSP), and the main DSP is configured to operate according to the signal output by the feedback digital signal processor (DSP).

Images