An audio signal processing system for a reading booth

Abstract

The embodiment of the present application discloses an audio signal processing system for a reading booth. The technical solution provided by the embodiment of the present application uses a DSP processor to connect a microphone input circuit and a background sound input circuit respectively, and receives a reading sound signal and a background sound signal respectively, wherein the reading sound signal is pre-echoed by an echo processing circuit to avoid the interference of the echo on the reading recording. The DSP processor obtains and outputs the corresponding mixed audio by mixing and digitally processing the reading sound signal and the background sound signal. When the user uses the reading booth to read aloud, he can hear the reading sound accompanied by background music, avoiding the monotony of the human voice recording playback, making the reading recording more beautiful, thereby optimizing the user's reading experience. In addition, the present application also uses a DSP processor to perform digital audio processing on the reading sound signal separately to obtain the corresponding original audio, so that the user can obtain a clear and clean original voice reading recording.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of audio processing technology, and in particular to an audio signal processing system for a reading booth. Background Art

[0002] As society continues to develop, people's spiritual needs are also growing. In order to improve the quality of life of urban residents and enrich people's spiritual needs, reading booths are set up in various areas of the city. Reading booths generally have functions such as reading, practicing, and speech training. They can guide people to participate in reading, calm down, return to their inner selves, and express their thoughts freely.

[0003] At present, most reading booths are set up as immersive soundproof spaces. The reading booths are equipped with recording and playback devices. When users read aloud, the recording equipment records the user's voice and plays it through the speakers. Users can read aloud in an immersive soundproof space to satisfy people's spiritual pursuits.

[0004] However, when the existing reading booths are in use, the reading recordings they generate are easily disturbed by noise such as echoes, and the reading recordings are relatively monotonous, resulting in a relatively poor reading experience for users. Summary of the invention

[0005] The embodiment of the present application provides an audio signal processing system for a reading booth, which can optimize reading recordings, eliminate recording echoes, and optimize the user's reading experience.

[0006] An audio signal processing system for a reading booth provided in an embodiment of the present application includes: a microphone input circuit, an echo processing circuit, a background sound input circuit, a DSP processor, an original sound output circuit, and a mixed sound output circuit;

[0007] The output end of the microphone input circuit is connected to the first input end of the echo processing circuit for inputting a reading sound signal and sending the reading sound signal to the echo processing circuit;

[0008] The output end of the echo processing circuit is connected to the DSP processor, so as to perform echo cancellation processing on the reading sound signal, and send the reading sound signal after the echo cancellation processing to the DSP processor;

[0009] The output end of the background sound input circuit is connected to the second input end of the DSP processor, so as to provide a background sound signal and send the background sound signal to the DSP processor;

[0010] The output end of the DSP processor is connected to the input end of the original sound output circuit, so as to perform digital audio processing on the reading sound signal to obtain the corresponding original sound audio, and send it to the original sound output circuit to output the original sound audio to the corresponding audio output interface;

[0011] The output end of the DSP processor is also connected to the input end of the mixed sound output circuit, which is used to mix the original audio and background sound signals and perform digital audio processing to obtain the corresponding mixed audio and send it to the mixed sound output circuit to output the mixed audio to the corresponding audio output interface.

[0012] Furthermore, the microphone input circuit includes four microphone input interfaces and a mixing module, the input end of the mixing module is connected to the output end of the microphone input interface, and is used to pick up the reading sound signal from the microphone input interface and perform mixing processing on the reading sound signal.

[0013] Furthermore, the circuit of the mixing module includes four first filter capacitors, four first resistors, an operational amplifier, a second resistor and a second filter capacitor. The first end of each of the first filter capacitors is respectively connected to an output end of the microphone input interface, the second end of each of the first filter capacitors is respectively connected to a first end of the first resistor, the second end of each of the first resistors is connected to an inverting input end of the operational amplifier, the non-inverting input end of the operational amplifier is used to access a reference voltage signal, the output end of the operational amplifier is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the second filter capacitor and the output end of the mixing module, and the second end of the second filter capacitor is grounded.

[0014] Furthermore, the microphone input interface supports docking with a dynamic microphone or a condenser microphone.

[0015] Furthermore, the microphone input circuit also includes a noise reduction processing module, the input end of the noise reduction processing module is connected to the output end of the mixing module, and the output end of the noise reduction processing module is connected to the echo processing circuit, which is used to perform noise reduction processing on the received reading sound signal and send it to the echo processing circuit.

[0016] Furthermore, the original sound output circuit includes an I2S output module and a mono output module. The I2S output module is used to receive the original sound audio sent by the DSP processor through the I2S bus, and directly output the original sound audio to the corresponding audio output interface; the mono output module is used to receive the original sound audio sent by the DSP processor through the I2S bus, perform digital-to-analog conversion on the original sound audio, amplify the signal by one time and switch to mono output to the corresponding audio output interface.

[0017] Furthermore, the mono output module is also connected to a reverberation processing circuit, the output end of the reverberation processing circuit is connected to the input end of an analog-to-digital converter, and the output end of the analog-to-digital converter is connected to the third input end of the DSP processor;

[0018] The reverberation processing circuit is used to perform reverberation processing on the original audio after digital-to-analog conversion of the mono output module, and send the original audio after reverberation processing to the analog-to-digital converter. The analog-to-digital converter performs analog-to-digital conversion on the original audio after reverberation processing and inputs it into the DSP processor for mixing with the background sound signal and digital audio processing to obtain the corresponding mixed audio.

[0019] Furthermore, the DSP processor includes a reverberation processing circuit, which is used to perform reverberation processing on the original audio obtained by the DSP processor through digital audio processing, and mix the reverberation-processed original audio with the background sound signal and perform digital audio processing to obtain the corresponding mixed audio.

[0020] Furthermore, the mixed sound output circuit includes a speaker output module, a line out output module and a headphone output module. The speaker output module is used to output the mixed sound audio to the speaker interface after performing Class D power amplifier processing; the line out output module is used to amplify the mixed sound audio by one times and output it to the line out interface; the headphone output module is used to amplify the mixed sound audio by one times and output it to the headphone interface.

[0021] Furthermore, the mixed sound output circuit also includes a control board output module, and the control board output module is used to amplify the mixed sound audio by one time and then output it to the memory of the control board.

[0022] The present application uses a DSP processor to connect to a microphone input circuit and a background sound input circuit respectively, and receives a reading sound signal and a background sound signal respectively, wherein the reading sound signal is pre-echoed by an echo processing circuit to avoid the interference of the echo on the reading recording. The DSP processor obtains the corresponding mixed audio and outputs it by mixing and digitally processing the reading sound signal and the background sound signal. When the user uses the reading booth to read aloud, he can hear the reading sound accompanied by background music, avoiding the monotony of the human voice recording playback, making the reading recording more beautiful and pleasant, thereby optimizing the user's reading experience.

[0023] In addition, the present application also performs digital audio processing on the reading sound signal through a DSP processor to obtain the corresponding original audio, so that users can obtain their own clear and clean original reading recordings to meet the different application requirements of users for reading recordings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of an audio signal processing system of a reading booth provided in an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of a dynamic microphone input circuit in an embodiment of the present application;

[0026] Figure 3 is a schematic diagram of a condenser microphone input circuit in an embodiment of the present application;

[0027] Figure 4 is a schematic diagram of a background sound input circuit in an embodiment of the present application;

[0028] Figure 5 is a circuit diagram of a mixing module in an embodiment of the present application;

[0029] Figure 6 is a schematic diagram of an original sound output circuit in an embodiment of the present application;

[0030] Figure 7 is a circuit diagram of a line out output module in an embodiment of the present application;

[0031] Figure 8 is a circuit diagram of an earphone output module in an embodiment of the present application;

[0032] Fig. 9 is a schematic diagram of a speaker output module circuit in an embodiment of the present application;

[0033] Fig.10 1 is a schematic diagram of the control board output module circuit in the embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present application clearer, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. It is understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for the convenience of description, only the part related to the present application but not all the contents are shown in the accompanying drawings. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow chart describes each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of each operation can be rearranged. The process can be terminated when its operation is completed, but it can also have additional steps not included in the accompanying drawings. The process can correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.

[0035] The audio signal processing system of the reading booth provided by the present application is intended to be used in the application scenario of the reading booth, and an echo processing circuit for the reading sound signal is provided to eliminate the interference of the echo in the user's reading process on the user's reading sound recording. In addition, the present application also respectively sets a microphone input circuit and a background sound input circuit to receive the reading sound signal and the background music sound signal respectively. And further, the two sound signals are mixed and digitally processed by a DSP processor to obtain the corresponding mixed audio and output. When the user uses the audio signal processing system of the reading booth of the embodiment of the present application to read aloud, the sound of the user's reading aloud can be played with background music, so as to optimize the processing of the reading recording and optimize the user's experience of the reading booth. Compared with the existing reading booth, when processing the user's reading sound, it usually simply converts the user's reading sound into stereo for playback. The reading recording heard by the user is only the sound of his own reading. This playback method of the reading recording is inevitably too monotonous, and the user's experience of the reading booth is relatively poor. In addition, since the reading recording will be broadcast from the speaker in real time when the user is reading aloud, this part of the reading recording is prone to echo in the relatively closed reading booth. The echo will be further recorded together with the user's reading voice through the microphone input circuit, which will cause the echo to interfere with the user's reading voice when the reading recording is played later, further affecting the user's reading experience. Based on this, the audio signal processing system of the reading booth of the embodiment of the present application is provided to solve the technical problems of echo interference and monotonous reading recording in the existing reading booth.

[0036] Example:

[0037] Figure 1 A structural diagram of an audio signal processing system of a reading booth provided in an embodiment of the present application is given, referring to Figure 1The audio signal processing system specifically includes: a microphone input circuit, an echo processing circuit, a background sound input circuit, a DSP (digital signal processing) processor, an original sound output circuit and a mixed sound output circuit; the output end of the microphone input circuit is connected to the first input end of the echo processing circuit for inputting a reading sound signal and sending the reading sound signal to the echo processing circuit; the output end of the echo processing circuit is connected to the DSP processor for performing echo cancellation processing on the reading sound signal and sending the reading sound signal after the echo cancellation processing to the DSP processor; the output end of the background sound input circuit is connected to the DSP The second input end of the processor is used to provide a background sound signal and send the background sound signal to the DSP processor; the output end of the DSP processor is connected to the input end of the original sound output circuit, and is used to perform digital audio processing on the reading sound signal to obtain the corresponding original sound audio, and send it to the original sound output circuit to output the original sound audio to the corresponding audio output interface; the output end of the DSP processor is also connected to the input end of the mixed sound output circuit, and is used to mix and digitally process the original sound audio and the background sound signal to obtain the corresponding mixed sound audio and send it to the mixed sound output circuit to output the mixed sound audio to the corresponding audio output interface.

[0038] Exemplarily, in the reading booth, a microphone, an audio signal processing system, a loudspeaker, a human-computer interaction terminal and other equipment are set. When the user reads aloud, the user's reading sound is collected through the microphone. If the user wants the loudspeaker to play the user's own voice, the audio signal processing system of the embodiment of the present application directly performs echo cancellation processing and digital audio processing on the reading sound signal to obtain the corresponding original audio, and the original audio is output to the loudspeaker in the reading booth for real-time playback, so that the user can hear his real-time reading sound through the loudspeaker. If the user wants the loudspeaker to play his own reading sound in real time with background music, the user selects a background music through the human-computer interaction terminal, indicating that the user's reading sound is mixed with the background music for playback. According to the user's selection, the human-computer interaction terminal extracts this background music from the internal storage and inputs the corresponding background sound signal into the audio signal processing system. The audio signal processing system receives the background sound signal and the user's reading sound signal, performs mixing and digital audio processing, obtains the mixed audio mixed with the two, and the mixed audio is output to the loudspeaker for playback, so that the user can hear his own reading sound accompanied by background music for real-time playback. This is to optimize the user experience.

[0039] Specifically, in the implementation of the present application, two channels of sound signals are provided by setting up a microphone input circuit and a background sound input circuit. Among them, the reading sound signal collected by the microphone is received through the microphone input circuit, and the pre-stored background sound signal is obtained through the background sound input circuit. When the user uses the reading booth, the user's reading sound signal (analog signal) is picked up in real time by the microphone, and the voltage amplitude of the picked up reading sound signal is amplified by 1 times, and the microphone is connected to the reading sound signal through the microphone input circuit. The microphone input circuit includes four microphone input interfaces and a mixing module. The microphone input interface supports two types of microphones: dynamic microphones and condenser microphones. Among them, the condenser microphone is powered by a 48V phantom power supply. Reference Figure 2-Figure 3 , providing dynamic microphone input circuit and condenser microphone input circuit. Through two different microphone input circuits, the reading sound signals collected by different microphones can be connected. Figure 5 , a circuit diagram of a mixing module is provided, wherein the input end of the mixing module is connected to the output end of the microphone input interface, and is used to pick up the reading sound signal from the microphone input interface and perform mixing processing on the reading sound signal. Furthermore, the microphone input circuit also includes a noise reduction processing module, wherein the input end of the noise reduction processing module is connected to the output end of the mixing module, and the output end of the noise reduction processing module is connected to the echo processing circuit, and is used to perform noise reduction processing on the received reading sound signal and send it to the echo processing circuit. The mixing module first mixes the sound signals received by each microphone input interface into a sound wave (mono), and then inputs it into the noise reduction processing module for noise reduction processing. Specifically, the circuit of the mixing module includes four first filter capacitors, four first resistors, an operational amplifier, a second resistor and a second filter capacitor, the first end of each of the first filter capacitors is respectively connected to the output end of the microphone input interface, the second end of each of the first filter capacitors is respectively connected to the first end of the first resistor, the second end of each of the first resistors is connected to the inverting input end of the operational amplifier, the in-phase input end of the operational amplifier is used to access the reference voltage signal, the output end of the operational amplifier is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the second filter capacitor and the output end of the mixing module, and the second end of the second filter capacitor is grounded. Further, since the noise is mainly a low-frequency sound wave, the noise reduction processing module uses an inverted sound wave equal to the external noise to eliminate the noise. The noise is neutralized by the inverted sound wave to eliminate the low-frequency noise of the outside world. After completing the noise elimination, the noise reduction processing module sends the reading sound signal to the echo processing circuit for echo elimination. In the embodiment of the present application, the sound signals input from each microphone input interface are first mixed into a sound wave, and then noise reduction and echo cancellation processing are performed, thereby eliminating the steps of separately denoising and echo cancellation of the sound signals input from each microphone input interface.

[0040] Further, since the reading sound signal collected by the microphone contains the echo generated by the sound played by the loudspeaker in the reading booth, therefore, when the reading sound signal is input into the DSP processor for digital audio processing, the embodiment of the present application will pre-echo the reading sound signal. The reading sound signal is input into the echo processing circuit through the noise reduction processing module. The echo processing circuit synchronously collects an audio signal at the output end of the sound source (original sound output circuit or mixed sound output circuit) for the echo generated in the reading booth space when the loudspeaker plays the sound, and performs a certain delay displacement and inversion on the audio signal. At the same time, according to different actual use conditions, the amplitude of the signal is amplified to different amplitude value ranges, and the processed audio signal is returned to the echo processing circuit as a reference input signal. The reference input signal is processed by logical addition with the reading sound signal, thereby canceling the echo, leaving a clear human voice, so as to realize the echo cancellation processing of the reading sound signal. In the embodiment of the present application, the noise reduction processing module and the echo processing circuit are integrated together. In practical applications, two different circuit modules can be set corresponding to the noise reduction and echo processing of the reading sound signal to process the sound signal respectively. In addition, the noise reduction and echo processing can also be set in the DSP processor, and the noise reduction and echo cancellation processing of the reading sound signal are performed in the DSP processor. By using the noise reduction module to eliminate low-frequency noise, and using the audio signal output by the sound source output end (original sound output circuit or mixed sound output circuit) as the reference input signal of the echo processing circuit, the sound played by the speaker and the echo when reading aloud are effectively eliminated, so that the human voice of the reading work outputted finally is clear and clean, and the reading experience of the user is improved.

[0041] On the other hand, refer to Figure 4 , providing a background sound input circuit portion of an embodiment of the present application, the background sound input circuit can also be connected to a central processing unit (CPU), the central processing unit stores a corresponding background sound signal, and is used to amplify the internally stored background sound signal by one time and send it to a DSP processor. Specifically, after the CPU synchronously decodes the audio file (background music) stored in the file data according to the instruction and separates the background sound signal, the background sound signal is input from the background sound input circuit in stereo, and the background sound signal is amplified by one time and then input into the DSP processor through A / D conversion. It can be understood that the CPU can be the CPU of the human-computer interaction terminal in the reading booth, which determines the background music selected by the user based on the human-computer interaction with the user, and extracts the corresponding background music from the internal storage and inputs it into the DSP processor. The CPU can also be a module set up separately by the system, which extracts the corresponding background music from the internal storage according to the instruction of the human-computer interaction terminal and inputs it into the DSP processor for further processing.

[0042] Afterwards, the reading sound signal and the background sound signal are respectively input into the DSP processor through different input terminals of the DSP processor for digital audio processing. Among them, according to whether the reading recording generated by the user's choice is the original audio of pure human voice or the mixed audio of mixed background music, the DSP processor adopts different processing methods for digital audio processing. If the user only needs the original audio of pure human voice, then in the DSP processor, the corresponding input reading sound signal first modifies the signal gain through volume adjustment according to actual needs, and then filters out the high-frequency and low-frequency signals through filtering and EQ equalization adjustment, and adjusts the gain of each frequency in the signal. Afterwards, the gain of the signal is adjusted again through volume adjustment. Here, the volume adjustment of the reading sound signal is twice, the first is the adjustment of the signal input level, and the second is the adjustment of the user level. Finally, by first copying the monophonic reading sound signal to the left channel, and then copying a copy to the right channel, the monophonic reading sound signal is converted into stereo, and the stereo conversion is realized, which can be output from the DSP processor to the original sound output circuit through the I2S bus.

[0043] Furthermore, the original sound output circuit includes an I2S output module and a mono output module. The I2S output module is used to receive the original sound audio sent by the DSP processor through the I2S bus, and directly output the original sound audio to the corresponding audio output interface; the mono output module is used to receive the original sound audio sent by the DSP processor through the I2S bus, perform digital-to-analog conversion on the original sound audio, amplify the signal by one time, and switch to mono output to the corresponding audio output interface. Figure 6 As shown, the original sound output circuit supports direct output of digital signal original sound audio through the I2S output module. It can also be converted into an analog signal through a mono output module using a D / A converter, and then output to the corresponding audio output interface after amplifying the mono sound once. The original sound audio can be transmitted through mono to reduce hardware costs. In this way, the processing and output of the original sound audio can be completed, and users can obtain the original sound audio through two audio output interfaces according to different needs.

[0044] On the other hand, if the user needs a mixed audio of a reading sound mixed with background music, the DSP processor performs digital audio processing according to the background sound signal and the reading sound signal. Among them, after the background sound signal enters the DSP processor, the gain of the background sound signal is changed by volume adjustment. The signal is further balanced and the overtone level of each frequency in the signal is modified. Among them, the adjustment of the equalization effect can be modified automatically, and it can also be modified by the user through the interactive interface of the human-computer interaction terminal. Afterwards, the background sound signal processed by the above-mentioned DSP processor and the background sound signal processed by digital audio are mixed into stereo through mixing processing to output to different mixed sound output circuits. It should be noted that when performing the mixing processing of the background sound signal and the reading sound signal, the source of the reading sound signal can be a mono audio signal processed by noise reduction and echo in the DSP processor, or it can be the above-mentioned stereo audio signal converted by mono, or it can be an audio signal after stereo reverberation processing.

[0045] Specifically, the reverberation processing circuit can be set in the original sound output circuit, or it can be set in the DSP processor. Among them, if it is set in the original sound output circuit, the reverberation processing circuit is connected to the mono output module, the output end of the reverberation processing circuit is connected to the input end of the analog-to-digital converter, and the output end of the analog-to-digital converter is connected to the third input end of the DSP processor. The reverberation processing circuit is used to perform reverberation processing on the original sound audio after the mono output module is converted by digital-to-analog conversion, and the original sound audio after the reverberation processing is sent to the analog-to-digital converter. The analog-to-digital converter performs analog-to-digital conversion on the original sound audio after the reverberation processing and inputs it into the DSP processor, which is used to mix with the background sound signal and perform digital audio processing to obtain the corresponding mixed sound audio. The reverberation module includes a delay time adjustment circuit, a reverberation amplitude adjustment circuit and a reverberation frequency adjustment circuit. After the corresponding reverberation processing and analog-to-digital conversion, it is input into the DSP processor, and filtering and EQ equalization adjustment are performed in the DSP processor, and the adjusted reading sound signal is processed with the original sound audio. If a reverberation processing circuit is provided in the DSP processor, the reverberation processing circuit is used to perform reverberation processing on the original sound audio obtained by the DSP processor through digital audio processing, and the original sound audio after reverberation processing is directly mixed with the background sound signal and digitally processed to obtain the corresponding mixed sound audio.

[0046] Finally, the stereo sound after the background sound signal and the reading sound signal are mixed is output to the mixed sound output circuit, which includes a speaker output module, a line out output module and a headphone output module. Among them, the circuit of the line out output module is as follows Figure 7 As shown in the figure, the line out output module is used to amplify the mixed audio by one time and then output it to the line out interface; the headphone output module is as shown in the figure. Figure 8As shown, the headphone output module is used to double the mixed audio and output it to the headphone interface; the speaker output module is as shown Fig. 9 As shown, the speaker output module is used to output the mixed sound audio to the speaker interface after being processed by a Class D power amplifier. In addition, in order to facilitate users to download their own reading recordings, the mixed sound output circuit also includes a control board output module. The control board output module is as shown in FIG. Fig.10 As shown, the control board output module is used to amplify the mixed audio by one time and then output it to the memory of the control board. Users can use the control board output module to download the mixed audio to the corresponding memory using related devices. Specifically, the first channel of the four audio output channels of the mixed output circuit is output to the speaker after the volume is adjusted, and the CLASS D amplifier is output; the second channel is output to the line out after the volume is adjusted, and the analog signal processed by the sound card is output to the audio output channel (reserved interface) on the audio device such as the speaker through the Line Out interface; the third channel is output to the headphone after the volume is adjusted, and the mixed audio is amplified by 1 time. The fourth channel is output to the control board (Android system board) after the volume is adjusted and amplified by 1 time. In addition, the format of the mixed audio supports common audio formats such as MP3, WAVE, CD, FLAC, etc. The works are automatically saved in the system's file server, and it also supports the use of mobile storage devices to copy audio files.

[0047] More specifically, in the embodiment of the present application, the background sound signal is divided into two paths after volume adjustment and equalization adjustment, one of which is mixed with the reading sound signal after volume, filtering and equalization adjustment in the DSP processor to generate mixed audio, and the mixed audio is output to the speaker output module and line out output module of the mixed output circuit. The other background sound signal is mixed with the reading sound signal after the above reverberation processing to generate mixed audio, and the mixed audio is output to the headphone output module and the control board output module. Different mixing methods are used to meet the needs of different output channels for mixed audio.

[0048] As described above, the microphone input circuit and the background sound input circuit are connected to the DSP processor respectively to receive the reading sound signal and the background sound signal respectively, wherein the reading sound signal is pre-echoed by the echo processing circuit to avoid the interference of the echo on the reading recording. The DSP processor obtains the corresponding mixed audio and outputs it by mixing and digital audio processing the reading sound signal and the background sound signal. When the user uses the reading booth to read aloud, he can hear the reading sound accompanied by background music, avoiding the monotony of the human voice recording playback, making the reading recording more beautiful and pleasant, thereby optimizing the user's reading experience.

[0049] In addition, the present application also performs digital audio processing on the reading sound signal through a DSP processor to obtain the corresponding original audio, so that users can obtain their own clear and clean original reading recordings to meet the different application requirements of users for reading recordings.

[0050] The above are only preferred embodiments of the present application and the technical principles used. The present application is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions that can be made by those skilled in the art will not deviate from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. An audio signal processing system for a reading booth, characterized in that: include: Microphone input circuit, echo processing circuit, background sound input circuit, DSP processor, original sound output circuit and mixed sound output circuit; The output end of the microphone input circuit is connected to the first input end of the echo processing circuit, and is used to input a reading sound signal, and send the reading sound signal to the echo processing circuit. The microphone input circuit includes four microphone input interfaces and a mixing module. The input end of the mixing module is connected to the output end of the microphone input interface, and is used to pick up the reading sound signal from the microphone input interface and perform mixing processing on the reading sound signal. The output end of the echo processing circuit is connected to the DSP processor, so as to perform echo cancellation processing on the reading sound signal, and send the reading sound signal after the echo cancellation processing to the DSP processor; The output end of the background sound input circuit is connected to the second input end of the DSP processor, so as to provide a background sound signal and send the background sound signal to the DSP processor; The output end of the DSP processor is connected to the input end of the original sound output circuit, and is used to perform digital audio processing on the reading sound signal to obtain the corresponding original sound audio, and send it to the original sound output circuit to output the original sound audio to the corresponding audio output interface. The original sound output circuit includes an I2S output module and a mono output module. The I2S output module is used to receive the original sound audio sent by the DSP processor through the I2S bus, and directly output the original sound audio to the corresponding audio output interface; the mono output module is used to receive the original sound audio sent by the DSP processor through the I2S bus, perform digital-to-analog conversion on the original sound audio, double the signal and switch to mono output to the corresponding audio output interface; The output end of the DSP processor is also connected to the input end of the mixed sound output circuit, which is used to mix the original audio and background sound signals and perform digital audio processing to obtain the corresponding mixed audio and send it to the mixed sound output circuit to output the mixed audio to the corresponding audio output interface.

2. The audio signal processing system of the reading booth according to claim 1, characterized in that: The circuit of the mixing module includes four first filter capacitors, four first resistors, an operational amplifier, a second resistor and a second filter capacitor. The first end of each of the first filter capacitors is connected to an output end of the microphone input interface, the second end of each of the first filter capacitors is connected to a first end of the first resistor, the second end of each of the first resistors is connected to an inverting input end of the operational amplifier, the non-inverting input end of the operational amplifier is used to access a reference voltage signal, the output end of the operational amplifier is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the second filter capacitor and the output end of the mixing module, and the second end of the second filter capacitor is grounded.

3. The audio signal processing system of the reading booth according to claim 1, characterized in that: The microphone input interface supports connecting to a dynamic microphone or a condenser microphone.

4. The audio signal processing system of the reading booth according to claim 1, characterized in that: The microphone input circuit also includes a noise reduction processing module, the input end of the noise reduction processing module is connected to the output end of the mixing module, and the output end of the noise reduction processing module is connected to the echo processing circuit, which is used to perform noise reduction processing on the received reading sound signal and send it to the echo processing circuit.

5. The audio signal processing system of the reading booth according to claim 4, characterized in that: The mono output module is also connected to a reverberation processing circuit, the output end of the reverberation processing circuit is connected to the input end of the analog-to-digital converter, and the output end of the analog-to-digital converter is connected to the third input end of the DSP processor; The reverberation processing circuit is used to perform reverberation processing on the original audio after digital-to-analog conversion of the mono output module, and send the original audio after reverberation processing to the analog-to-digital converter. The analog-to-digital converter performs analog-to-digital conversion on the original audio after reverberation processing and inputs it into the DSP processor for mixing with the background sound signal and digital audio processing to obtain the corresponding mixed audio.

6. The audio signal processing system of the reading booth according to claim 1, characterized in that: The DSP processor includes a reverberation processing circuit, which is used to perform reverberation processing on the original audio obtained by the DSP processor through digital audio processing, and mix the original audio after reverberation processing with the background sound signal and perform digital audio processing to obtain the corresponding mixed audio.

7. The audio signal processing system of the reading booth according to claim 1, characterized in that: The mixed sound output circuit includes a speaker output module, a line out output module and a headphone output module. The speaker output module is used to output the mixed sound audio to the speaker interface after performing Class D power amplifier processing; the line out output module is used to amplify the mixed sound audio by one time and output it to the line out interface; the headphone output module is used to amplify the mixed sound audio by one time and output it to the headphone interface.

8. The audio signal processing system of the reading booth according to claim 7, characterized in that: The mixed sound output circuit also includes a control board output module, and the control board output module is used to amplify the mixed sound audio by one time and then output it to the memory of the control board.

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