WO2022048376A1 - Sound field expansion method and circuit, electronic device, and storage medium - Google Patents

Abstract

Embodiments of the present application provide a sound field expansion method and circuit, an electronic device, and a storage medium. The circuit comprises: an early-stage reflected sound circuit and a later-stage reflected sound circuit. The early-stage reflected sound circuit comprises a plurality of comb filters connected in parallel, and gains of the plurality of comb filters are different; the later-stage reflected sound circuit is connected to an output end of the early-stage reflected sound circuit, and the later-stage reflected sound circuit comprises an all-pass filter circuit, and the all-pass filter circuit comprises a plurality of all-pass filters which are connected in series; the early-stage reflected sound circuit is used for filtering a first sound signal by utilizing the plurality of comb filters to obtain an early-stage reflected sound signal, the first sound signal being obtained according to an input sound signal; the later-stage reflected sound circuit is used for carrying out phase shift on a first input signal by utilizing the plurality of all-pass filters to obtain a later-stage reflected sound signal so as to obtain an output sound signal according to the input sound signal and the later-stage reflected sound signal, wherein the first input signal is an early-stage reflected sound signal or is obtained according to the early-stage reflected sound signal.

Description

A sound field expansion method, circuit, electronic device and storage medium

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on the Chinese patent application with the application number of 202010917416.5 and the filing date of September 3, 2020, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated by reference into this application.

technical field

The present application relates to the technical field of audio processing, and in particular, to a sound field expansion method, a circuit, an electronic device and a storage medium.

Background technique

The existing stereo sound field expansion technology is that the bluetooth chip at the earphone end converts the received analog audio signal to digital signal to obtain a digital signal, and at the same time separates the left and right channel signals, adds/subtracts the left and right channel signals, and reduces them. Infinite Impulse Response (IIR) low-pass filter processing, adding to one of the input channels to form an output channel, and then filtering the signal processed by the IIR low-pass filter through Hilbert transform, The amplitude of each frequency component in the frequency domain remains unchanged, but the phase is shifted by 90°, and then it is added to another input channel to form an output channel. Convert from electrical signals to acoustic signals. So as to achieve the purpose of expanding the stereo sound field.

However, using the Hilbert transform filter to perform a 90° phase shift usually requires a higher order Finite Impulse Response (FIR) filter to reduce the influence on the amplitude characteristics of the signal at each frequency. This results in a large amount of computation for the expansion of the stereo sound field, thereby increasing the power consumption of the earphone.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a sound field expansion method, a circuit, an electronic device, and a storage medium, which can reduce the computational complexity of stereo sound field expansion and the power consumption of earphones.

The technical solution of the present application is realized as follows:

The embodiment of the present application provides a sound field expansion circuit, the sound field expansion circuit includes an early reflected sound circuit and a late reflected sound circuit;

The early reflected sound circuit includes a plurality of comb filters connected in parallel, and the gains of the plurality of comb filters are different;

The late reflected sound circuit is connected to the output end of the early reflected sound circuit, the late reflected sound circuit includes an all-pass filter circuit, and the all-pass filter circuit includes a plurality of all-pass filters connected in series;

The early reflected sound circuit is used to filter the first sound signal by using the plurality of comb filters to obtain the early reflected sound signal, and the first sound signal is obtained according to the input sound signal;

The late-stage reflected sound circuit is used to phase-shift the first input signal by using the plurality of all-pass filters to obtain a late-stage reflected sound signal, so as to obtain a late-stage reflected sound signal according to the input sound signal and the late-stage reflected sound signal, An output acoustic signal is obtained, wherein the first input signal is the early reflected acoustic signal or is obtained according to the early reflected acoustic signal.

An embodiment of the present application provides an electronic device, the electronic device includes: a left channel input terminal, a right channel input terminal, a sound field preprocessing circuit, a left channel sound field expansion circuit, a right channel sound field expansion circuit, a left channel sound field expansion circuit, and a left channel sound field expansion circuit. An output circuit and a right channel output circuit, the left channel sound field expansion circuit and the right channel sound field expansion circuit are the same as the sound field expansion circuit described in any of the above; wherein,

The left channel input terminal and the right channel input terminal are respectively connected with the input terminal of the sound field preprocessing circuit, and the output terminal of the sound field preprocessing circuit is respectively connected with the input terminal of the left channel sound field expansion circuit. It is connected with the input end of the right channel sound field expansion circuit, the output end of the left channel sound field expansion circuit and the left channel input end are respectively connected with the input end of the left channel output circuit, and the right channel sound field expansion circuit is connected with the input end of the left channel output circuit. The output end of the channel sound field expansion circuit and the right channel input end are respectively connected with the input end of the right channel output circuit;

The left channel input terminal is used for inputting the left channel input sound signal, and the right channel input terminal is used for inputting the right channel input sound signal;

the acoustic signal preprocessing circuit, configured to preprocess the left channel input signal and the right channel input signal to obtain the first acoustic signal;

The left channel sound field expansion circuit is used for processing the first sound signal to obtain the left channel late reflection sound signal;

The left channel output circuit is used for processing the left channel input sound signal and the left channel late reflection sound signal to obtain the left channel output sound signal;

The right channel sound field expansion circuit is used for processing the first sound signal to obtain the right channel late reflected sound signal;

The right channel output circuit is used for processing the right channel input sound signal and the right channel post-reflection sound signal to obtain a right channel output sound signal.

An embodiment of the present application provides a sound field expansion method, which is applied to the sound field expansion circuit. The sound field expansion circuit includes: an early reflected sound circuit composed of a plurality of comb filters connected in parallel, and an output of the early reflected sound circuit with the early reflected sound circuit A late-stage reflected sound circuit connected to the terminals, the late-stage reflected sound circuit is composed of a plurality of all-pass filters connected in series, and the method further includes:

Preprocessing the input acoustic signal to obtain a first acoustic signal;

Filter the first acoustic signal by using the plurality of comb filters to obtain an early reflected acoustic signal;

Phase-shift the early reflected acoustic signals by using the plurality of all-pass filters to obtain late reflected acoustic signals;

According to the input acoustic signal and the later reflected acoustic signal, an output acoustic signal corresponding to the input acoustic signal is obtained.

An embodiment of the present application provides an electronic device, the electronic device includes: a processor, a memory, and a communication bus; when the processor executes a running program stored in the memory, the method as described in any of the above is implemented.

An embodiment of the present application provides a storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements any of the methods described above.

Description of drawings

1 is a schematic structural diagram of a stereo sound field expansion circuit in the prior art;

FIG. 2(a) is a schematic structural diagram 1 of a sound field expansion circuit provided by an embodiment of the present application;

FIG. 2(b) is a second structural schematic diagram of a sound field expansion circuit provided by an embodiment of the application;

3 is a schematic diagram of the circuit structure of an exemplary early reflected sound circuit provided by an embodiment of the present application;

4 is a schematic diagram of the circuit structure of an exemplary late-stage reflected sound circuit provided by an embodiment of the present application;

5 is a schematic diagram of a circuit structure of an exemplary low-pass filter provided by an embodiment of the present application;

FIG. 6 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

7 is a schematic structural diagram of an exemplary sound field expansion circuit provided by an embodiment of the present application;

8 is a flowchart of a sound field expansion method provided by an embodiment of the present application;

FIG. 9 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

detailed description

In a first aspect, an embodiment of the present application proposes a sound field expansion circuit, and the sound field expansion circuit includes: an early reflected sound circuit and a later reflected sound circuit;

The early reflected sound circuit includes a plurality of comb filters connected in parallel, and the gains of the plurality of comb filters are different;

The late reflected sound circuit is connected to the output end of the early reflected sound circuit, the late reflected sound circuit includes an all-pass filter circuit, and the all-pass filter circuit includes a plurality of all-pass filters connected in series;

The early reflected sound circuit is used to filter the first sound signal by using the plurality of comb filters to obtain the early reflected sound signal, and the first sound signal is obtained according to the input sound signal;

The late-stage reflected sound circuit is used to phase-shift the first input signal by using the plurality of all-pass filters to obtain a late-stage reflected sound signal, so as to obtain an output according to the input sound signal and the late-stage reflected sound signal An acoustic signal, wherein the first input signal is the early reflected acoustic signal or is obtained from the early reflected acoustic signal.

In the above circuit, the late reflected sound circuit further includes: a first adder and a low-pass feedback circuit; the first input end of the first adder is connected to the output end of the early reflected sound circuit, and the first adder is connected to the output end of the early reflected sound circuit. The second input end of an adder is connected to the output end of the low-pass feedback circuit, the output end of the first adder is connected to the input end of the all-pass filter circuit, and the the output end is connected to the input end of the low-pass feedback circuit;

The low-pass feedback circuit is used to filter and control the sound of the later reflected sound signal to obtain a feedback signal, and transmit the feedback signal to the second input end of the first adder;

the first adder, configured to add the feedback signal and the early reflected sound signal to obtain the first input signal;

The plurality of all-pass filters are also used for phase-shifting the first input signal to obtain the later reflected sound signal.

In the above circuit, the low-pass feedback circuit includes a low-pass filter and a feedback gain amplifier, the input end of the low-pass filter is connected to the output ends of the plurality of all-pass filters, and the low-pass filter The output end of the feedback gain amplifier is connected to the input end of the feedback gain amplifier, and the output end of the feedback gain amplifier is connected to the second input end of the first adder;

The low-pass filter is used to filter the late-stage reflected acoustic signal to obtain a first filtered acoustic signal, wherein the high-frequency sound attenuation of the first filtered acoustic signal is greater than the low-frequency sound attenuation;

The feedback gain amplifier is used for performing sound control on the first filtered sound signal to obtain the feedback signal.

In the above circuit, the early reflected sound circuit further comprises: a plurality of gain amplifiers and a second adder, the plurality of gain amplifiers are in one-to-one correspondence with the plurality of comb filters, and the input end of each gain amplifier are respectively connected in series with the output ends of the corresponding comb filters, the gain values of the multiple gain amplifiers are different, and the output ends of the multiple gain amplifiers are connected to the second adder;

The plurality of comb filters and the plurality of gain amplifiers are used for filtering and signal gain respectively for the first acoustic signal to obtain a plurality of delayed attenuated acoustic signals, the plurality of delayed attenuated acoustic signals The signal delay and signal attenuation are different;

The second adder is configured to add the plurality of delayed attenuated acoustic signals to obtain the early reflected acoustic signals.

In the above circuit, the signal delay of the comb filter is greater than the signal delay of the all-pass filter.

In the above circuit, the comb filter includes a third adder, a first delay, a first feedback gain amplifier and a first low-pass filter, wherein the first low-pass filter is formed by a second delay It consists of a timer, a first gain amplifier and a fourth adder;

The first input end of the third adder is connected to the input of the comb filter, the output end of the first adder is connected to the input end of the first delay device, and the output end of the first delay device is connected to the input end of the first delay device. The output end is connected to the output end of the comb filter and the first input end of the fourth adder, the second input end of the fourth adder is connected to the output end of the first gain amplifier, and the second input end of the fourth adder is connected to the output end of the first gain amplifier. The input end of a gain amplifier is connected to the output end of the second delay device, the input end of the second delay device and the output end of the fourth adder are connected to the input end of the first feedback gain amplifier, The output terminal of the first feedback gain amplifier is connected to the second input terminal of the third adder.

In the above circuit, the all-pass filter includes: a fifth adder, a third delay device, a sixth adder, a second gain amplifier, a third gain amplifier and a second feedback gain amplifier;

The first input end of the fifth adder is connected to the input of the all-pass filter, and the output end of the fifth adder is respectively connected to the input end of the third delayer and the output end of the second gain amplifier. input end, the output end of the third delay device is respectively connected to the input end of the third gain amplifier and the input end of the second feedback gain amplifier, the output end of the third gain amplifier and the second gain amplifier The output end is connected to the input end of the sixth adder, the output end of the second feedback gain amplifier is connected to the second input end of the fifth adder, and the output end of the sixth adder is connected to the all-pass filter output of the device.

In the above circuit, the low-pass filter is a wireless impulse response IIR low-pass filter.

In a second aspect, an embodiment of the present application proposes an electronic device, the electronic device includes: a left channel input terminal, a right channel input terminal, a sound field preprocessing circuit, a left channel sound field expansion circuit, and a right channel sound field expansion circuit , a left channel output circuit and a right channel output circuit, the left channel sound field expansion circuit and the right channel sound field expansion circuit are the same as the circuits described in any of the above; wherein,

The left channel input terminal and the right channel input terminal are respectively connected with the input terminal of the sound field preprocessing circuit, and the output terminal of the sound field preprocessing circuit is respectively connected with the input terminal of the left channel sound field expansion circuit. It is connected with the input end of the right channel sound field expansion circuit, the output end of the left channel sound field expansion circuit and the left channel input end are respectively connected with the input end of the left channel output circuit, and the right channel sound field expansion circuit is connected with the input end of the left channel output circuit. The output end of the channel sound field expansion circuit and the right channel input end are respectively connected with the input end of the right channel output circuit;

The left channel input terminal is used for inputting the left channel input sound signal, and the right channel input terminal is used for inputting the right channel input sound signal;

the acoustic signal preprocessing circuit, configured to preprocess the left channel input signal and the right channel input signal to obtain the first acoustic signal;

The left channel sound field expansion circuit is used for processing the first sound signal to obtain the left channel late reflection sound signal;

The left channel output circuit is used for processing the left channel input sound signal and the left channel late reflection sound signal to obtain the left channel output sound signal;

The right channel sound field expansion circuit is used for processing the first sound signal to obtain the right channel late reflected sound signal;

The right channel output circuit is used for processing the right channel input sound signal and the right channel post-reflection sound signal to obtain a right channel output sound signal.

In the above electronic device, the left channel sound field expansion circuit includes a left channel early reflection sound circuit and a left channel late reflection sound circuit, and the right channel sound field expansion circuit includes a right channel early reflection sound circuit and a right sound channel. A late-channel reflected sound circuit, wherein the left channel early reflected sound circuit and the right channel early reflected sound circuit are the same as the early reflected sound circuit described in any of the above; the left channel late reflected sound circuit and the later reflected sound circuit of the right channel is the same as the later reflected sound circuit described in any of the above;

The output end of the left channel early reflected sound circuit is connected with the input end of the left channel late reflected sound circuit; the output end of the right channel early reflected sound circuit is connected to the output end of the right channel late reflected sound circuit. input connection.

In the above electronic device, the electronic device further includes: a communication module, a left channel speaker and a right channel speaker; the communication module is connected to the left channel input end and the right channel input end, the The output end of the left channel output circuit is connected to the left channel speaker, and the output end of the right channel output circuit is connected to the right channel speaker;

the communication module for receiving audio data and separating the audio data into the left channel input sound signal and the right channel input sound signal;

The left channel speaker is used for playing the left channel output sound signal, and the right channel speaker is used for playing the right channel output sound signal.

In a third aspect, an embodiment of the present application proposes a sound field expansion method, which is applied to the sound field expansion circuit, where the sound field expansion circuit includes: an early reflected sound circuit composed of a plurality of comb filters connected in parallel and a The late-stage reflected sound circuit connected to the output end of the reflected sound circuit, the late-stage reflected sound circuit is composed of a plurality of all-pass filters connected in series, and the method further includes:

Preprocessing the input acoustic signal to obtain a first acoustic signal;

Filter the first acoustic signal by using the plurality of comb filters to obtain an early reflected acoustic signal;

Phase-shift the first input signal by using the plurality of all-pass filters to obtain a later reflected sound signal, wherein the first input signal is the early reflected sound signal or obtained according to the early reflected sound signal;

According to the input acoustic signal and the later reflected acoustic signal, an output acoustic signal corresponding to the input acoustic signal is obtained.

In the above method, the use of a plurality of comb filters to filter the first acoustic signal to obtain an early reflected acoustic signal includes:

Using the plurality of comb filters to filter the first acoustic signal, respectively, to obtain a plurality of time-delayed attenuated acoustic signals, the signal delay and signal attenuation of the plurality of time-delayed attenuated acoustic signals are different;

The multiple delayed attenuated acoustic signals are added to obtain the early reflected acoustic signals.

In the above method, the use of multiple all-pass filters to phase-shift the first input signal to obtain a later reflected acoustic signal includes:

Perform filtering and sound control on the later reflected sound signal to obtain a feedback signal;

adding the feedback signal and the early reflected sound signal to obtain the first input signal;

Using the plurality of all-pass filters, phase-shift the first input signal to obtain the late-stage reflected acoustic signal.

In the above method, the input acoustic signal includes: a left channel input acoustic signal and a right channel input acoustic signal; the preprocessing of the input acoustic signal to obtain the first acoustic signal includes:

The first sound signal is obtained by performing signal addition or signal subtraction and reduction operations on the left channel input sound signal and the right channel input sound signal.

A fourth aspect, an embodiment of the present application proposes an electronic device, and the electronic device includes: a processor, a memory, and a communication bus; the processor executes the following method when executing a running program stored in the memory:

Preprocessing the input acoustic signal to obtain a first acoustic signal;

Filter the first acoustic signal by using the plurality of comb filters to obtain an early reflected acoustic signal;

Phase-shift the first input signal by using the plurality of all-pass filters to obtain a later reflected sound signal, wherein the first input signal is the early reflected sound signal or obtained according to the early reflected sound signal;

According to the input acoustic signal and the later reflected acoustic signal, an output acoustic signal corresponding to the input acoustic signal is obtained.

In the above electronic device, the processor is further configured to filter the first acoustic signal by using the multiple comb filters to obtain multiple delayed attenuated acoustic signals, the multiple delayed attenuated acoustic signals The signal delay and signal attenuation are different; the multiple delayed and attenuated acoustic signals are added to obtain the early reflected acoustic signal.

In the above electronic device, the processor is further configured to filter and soundly control the late reflected sound signal to obtain a feedback signal; and add the feedback signal and the early reflected sound signal to obtain the the first input signal; using the plurality of all-pass filters to phase-shift the first input signal to obtain the later reflected sound signal.

In the above electronic device, the input sound signal includes: a left channel input sound signal and a right channel input sound signal;

The processor is further configured to perform signal addition, signal subtraction, and reduction operations on the left channel input sound signal and the right channel input sound signal to obtain the first sound signal.

In a fifth aspect, an embodiment of the present application provides a storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements any of the methods described above.

Embodiments of the present application provide a sound field expansion method, circuit, electronic device, and storage medium. The sound field expansion circuit includes: an early reflected sound circuit and a later reflected sound circuit, and the early reflected sound circuit includes a plurality of comb filters connected in parallel, The gains of the multiple comb filters are different; the late reflected sound circuit is connected to the output end of the early reflected sound circuit, and the late reflected sound circuit includes an all-pass filter circuit, and the all-pass filter circuit includes a plurality of all-pass filters connected in series The early reflected sound circuit is used to filter the first sound signal by using a plurality of comb filters to obtain the early reflected sound signal, and the first sound signal is obtained according to the input sound signal; the later reflected sound circuit is used to use multiple comb filters. The first input signal is phase-shifted by an all-pass filter to obtain a later reflected acoustic signal, so as to obtain an output acoustic signal according to the input acoustic signal and the later reflected acoustic signal, wherein the first input signal is an early reflected acoustic signal or a The reflected acoustic signal is obtained. With the above implementation scheme, the early reflected sound circuit of the sound field expansion circuit is composed of multiple comb filters in parallel, and the later reflected sound circuit is composed of multiple all-pass filters connected in series. The stereo sound field expansion can be realized by connecting multiple all-pass filters in series. Since the comb filter and the all-pass filter mainly implement multiplication and addition operations, the multiplication and addition operations in the Bluetooth chip can usually be performed within one clock cycle. Completed, thereby reducing the amount of operation of the stereo sound field expansion and the power consumption of the headset. It should be understood that the specific embodiments described herein are merely illustrative of the present application. It is not intended to limit this application.

1 is a structural diagram of a stereo sound field expansion circuit 1 in the related art, wherein the stereo sound field expansion circuit 1 includes a left channel input end 10, a right channel input end 11, an adder-subtractor 12, an IIR low-pass filter 13, Gain amplifier 14 , Hilbert filter 15 , adder 16 , adder 17 , left channel output 18 and right channel output 19 . The input end of the adder-subtractor 12 is respectively connected to the left channel input end 10 and the right channel input end 11, the output end of the adder-subtractor 12 is connected to the IIR low-pass filter 13, and the output end of the IIR low-pass filter 13 is connected to The gain amplifier 14 and the output end of the gain amplifier 14 are respectively connected to the Hilbert filter 15 and one input end of the adder 16, the other input end of the adder 16 is connected to the right channel input end 11, and the output end of the adder 16 The output end of the Hilbert filter 15 is connected to one input end of the adder 17, the other input end of the adder 17 is connected to the left channel input end 10, and the adder 17 The output terminal is connected to the right channel output terminal 19.

Referring to FIG. 1, the signal flow of the stereo sound field expansion method can be as follows: the left channel signal and the right channel signal are added/subtracted, and then processed by an IIR low-pass filter, and added with the left input channel to form a left channel. Output channel; at the same time, the signal processed by the IIR low-pass filter is passed through the Hilbert filter, and then added to the right input channel to form the right output channel.

Using the Hilbert transform filter to perform a 90° phase shift usually requires a higher-order FIR filter to reduce the impact on the amplitude characteristics of each frequency signal. The increase in power consumption has a greater impact on the battery life of the headset. In order to solve the above problems, the embodiments of the present application propose a sound field expansion circuit, method and storage medium, which will be specifically described by the following embodiments.

The embodiment of the present application provides a sound field expansion circuit 2. As shown in FIG. 2(a), the sound field expansion circuit 2 may include: an early reflected sound circuit 20 and a later reflected sound circuit 21,

The early reflected sound circuit 20 includes a plurality of comb filters 200 connected in parallel, and the gains of the multiple comb filters 200 are different;

The late reflected sound circuit 21 is connected to the output end of the early reflected sound circuit 20, the late reflected sound circuit 21 includes an all-pass filter circuit 210, and the all-pass filter circuit 210 includes a plurality of all-pass filters connected in series;

The early reflected sound circuit 20 is used to filter the first sound signal by using a plurality of comb filters 200 respectively to obtain the early reflected sound signal, and the first sound signal is obtained according to the input sound signal;

The late-stage reflected sound circuit 21 is used to phase-shift the first input signal by using a plurality of all-pass filters 210 to obtain a late-stage reflected sound signal, so as to obtain an output sound signal according to the input sound signal and the late-stage reflected sound signal, wherein the first An input signal is the early reflected sound signal or is obtained from the early reflected sound signal.

The sound field expansion circuit provided by the embodiment of the present application is applied to a scenario of expanding a stereo sound field when a stereo signal is played.

The sound field expansion circuit in the embodiment of the present application may be applied to an earphone or a speaker of an electronic device, and may be selected according to the actual situation, which is not specifically limited in the embodiment of the present application.

In the embodiments of the present application, the earphones may be Bluetooth neck-mounted earphones, true wireless stereo Bluetooth earphones, etc., which are specifically selected according to actual conditions, and are not specifically limited in the embodiments of the present application.

The embodiments of the present application are described by taking the application to an earphone as an example. The Bluetooth chip at the earphone end performs analog-to-digital conversion on the received analog audio signal to obtain a digital signal, and separates the digital signal into a left channel output sound signal and a right channel output sound signal. After that, the sound field expansion circuit preprocesses the left channel input sound signal and the right channel input sound signal to obtain the first sound signal.

In the embodiment of the present application, the first acoustic signal is filtered by a plurality of comb filters in parallel and output to simulate the early reflected sound of the sound field, wherein the output of each comb filter has a different gain and the gain is adjustable.

In the embodiment of the present application, the number of the plurality of comb filters may be 6, 8, 10, etc., which are specifically selected according to the actual situation, which is not specifically limited in the embodiment of the present application.

It can be understood that the structure of the comb filter 200 is shown in FIG. 3 , including an adder 301 , a delay device 302 , a feedback gain amplifier 303 and a low-pass filter 304 , wherein the low-pass filter 304 is composed of a delay device 3040 , a gain amplifier 3041 and an adder 3042, the first input end of the adder 301 is connected to the input of the comb filter, the output end of the adder 301 is connected to the delay device 302, and the output end of the delay device 302 is connected to the comb filter The output end of the adder 3042 and the first input end of the adder 3042, the second input end of the adder 3042 is connected to the output end of the gain amplifier 3041, the input end of the gain amplifier 3041 is connected to the output end of the delayer 3040, and the input end of the delayer The output end of the adder 3042 is connected to the input end of the feedback gain amplifier 303 , and the output end of the feedback gain amplifier 303 is connected to the second input end of the adder 301 . The specific parameter values of the delayer 302 and the delayer 3040 can be selected according to the actual situation, which is not specifically limited in this embodiment of the present application; the specific values of the gain amplifier 3041 and the feedback gain amplifier 303 can be selected according to the actual situation, The embodiments of the present application do not make specific limitations.

It should be noted that the comb filter shown in FIG. 3 is an optional structure of the comb filter in the embodiment of the present application, and is not limited to the above-mentioned comb filter structure in practical application, and the specific structure can be determined according to the actual situation. selection, which is not specifically limited in the embodiments of the present application.

It can be understood that the first acoustic signal can be filtered in the comb filter only by delaying and multiplying and adding operations. The multiplying and adding operations in the Bluetooth chip can usually be completed within one clock cycle. This greatly reduces the amount of computation in the expansion of the stereo sound field.

In the embodiment of the present application, the outputs of the multiple comb filters have different gains, and the first acoustic signal undergoes different degrees of sound attenuation after being filtered by the multiple comb filters respectively.

In the embodiment of the present application, the function of the all-pass filter is to keep the amplitude of each frequency component in the frequency domain unchanged in the whole frequency band, and to generate a certain degree of phase shift in phase. The first input signal is sequentially phase-shifted by a plurality of series-connected all-pass filters to obtain a later reflected sound signal, wherein the first input signal is an early reflected sound signal or a signal obtained according to the early reflected sound signal.

In the embodiment of the present application, the number of all-pass filters may be 4, 6, 8, etc., which are specifically selected according to the actual situation, which is not specifically limited in the embodiment of the present application.

It can be understood that the structure of the all-pass filter 210 is shown in FIG. 4 , including an adder 401 , a delay device 402 , an adder 403 , a gain amplifier 404 , a gain amplifier 405 and a feedback gain amplifier 406 , wherein the adder 401 has a The first input terminal is connected to the input of the all-pass filter, the output terminal of the adder 401 is connected to the delay device 402 and the gain amplifier 404 respectively, and the output terminal of the delay device 402 is respectively connected to the gain amplifier 405 and the feedback gain amplifier 406. The gain amplifier 405 The output end of the gain amplifier 404 and the output end of the gain amplifier 404 are connected to the input end of the adder 403, the output end of the feedback gain amplifier 406 is connected to the second input end of the adder 401, and the output end of the adder 403 is connected to the output of the all-pass filter. The specific parameter values of the timer 402 can be selected according to the actual situation, which is not specifically limited in this embodiment of the present application; The examples are not specifically limited.

It should be noted that the all-pass filter in FIG. 4 is an optional all-pass filter structure provided by the embodiment of the present application, and is not limited to the above-mentioned all-pass filter structure in practical application, and the specific structure may be based on actual conditions. selection, which is not specifically limited in the embodiments of the present application.

It can be understood that the filtering process of the first input signal can be realized only by delaying and multiplying and adding operations in the all-pass filter. The multiplying and adding operations in the Bluetooth chip can usually be completed within one clock cycle. This greatly reduces the amount of computation in the expansion of the stereo sound field.

It can be understood that the signal delay of the comb filter is greater than that of the all-pass filter.

In the embodiment of the present application, since the signal delay of the comb filter is greater than that of the all-pass filter, the signal delay of the early reflected sound signal is greater than the signal delay of the later reflected sound signal, so that the later reflected sound signal has a longer delay. The sound density is greater than that of the early reflected sound signal, so that a real stereo sound field effect can be simulated.

It can be understood that, the gain and delay of each comb filter and all-pass filter unit can adopt asymmetric parameters to reduce the correlation of the left and right channel signals to enhance the sound field width.

In this embodiment of the present application, the delay size may be in units of digital signal samples.

It can be understood that, as shown in FIG. 2( a ), the late-stage reflected sound circuit 21 further includes: a first adder 212 and a low-pass feedback circuit 211 ; The output end is connected, the second input end of the first adder 212 is connected with the output end of the low-pass feedback circuit 211, the output end of the first adder 212 is connected with the input end of the all-pass filter circuit 210, and the all-pass filter circuit The output end of 210 is connected with the input end of the low-pass feedback circuit;

The low-pass feedback circuit 211 is used to filter and control the sound of the later reflected sound signal to obtain a feedback signal, and transmit the feedback signal to the second input end of the first adder;

The first adder 212 is used to add the feedback signal and the early reflected sound signal to obtain the first input signal,

The multiple all-pass filters are also used for phase-shifting the first input signal to obtain a later reflected sound signal.

In the embodiment of the present application, the late-stage reflected sound circuit further includes a low-pass feedback circuit and a first adder. Specifically, the output end of the early-stage reflected sound circuit and the output end of the low-pass feedback circuit are connected to the input end of the first adder, The output end of the first adder is connected to a plurality of all-pass filters in series, and the output ends of the plurality of all-pass filters are connected to the input end of the low-pass feedback circuit, so that the later reflected sound is filtered by the low-pass feedback circuit. After the sound control is performed, the signal is added with the early reflected sound signal to obtain the first input signal, and then the first input signal is input into a plurality of all-pass filters to obtain the late reflected sound signal, so as to increase the late reflected sound density.

In the embodiment of the present application, the design of the low-pass feedback circuit can reduce the number of all-pass filters, thereby reducing the amount of computation when the sound field is expanded.

Optionally, referring to FIG. 2( a ), as shown in FIG. 2( b ), the low-pass feedback circuit 211 includes a low-pass filter 2110 and a feedback gain amplifier 2111 , and the input end of the low-pass filter 2110 is connected to a plurality of all-pass The output end of the filter 210 is connected, the output end of the low-pass filter 2110 is connected with the input end of the feedback gain amplifier 2111, and the output end of the feedback gain amplifier 2111 is connected with the second input end of the first adder 212;

The low-pass filter 2110 is used to filter the later reflected acoustic signal to obtain the first filtered acoustic signal, and the high-frequency sound attenuation of the first filtered acoustic signal is greater than the low-frequency sound attenuation;

The feedback gain amplifier 2111 is used for performing sound control on the first filtered sound signal to obtain a feedback signal.

In this embodiment of the present application, the low-pass filter may be an IIR low-pass filter.

In the embodiment of the present application, a schematic structural diagram of the low-pass filter is shown in FIG. 5 , including a delay device 501 , a gain amplifier 502 and an adder 503 , wherein the input end of the adder 503 is respectively connected to the output end of the gain amplifier 502 and the adder 503 . The output end of the all-pass filter and the output end of the adder 503 are respectively connected to the feedback gain amplifier and the delayer 501 , and the output end of the delayer 501 is connected to the input end of the gain amplifier 502 .

In the embodiment of the present application, the feedback gain amplifier 2111 is used to control the size of the reflected sound in the later stage, and the IIR low-pass filter is used to simulate the attenuation of high-frequency sound in the air faster than the attenuation of low-frequency sound. By adjusting the feedback gain amplifier 2111, the sound field widening can be controlled effect, so as to simulate the sound field of different reverberation, such as valley, cinema, indoor and other environments.

Optionally, as shown in FIG. 2(a) and FIG. 2(b), the early reflected sound circuit 20 further includes: a plurality of gain amplifiers 201 and a second adder 202, a plurality of gain amplifiers 201 and a plurality of comb filters. There is a one-to-one correspondence with each of the gain amplifiers 200, the input end of each gain amplifier 201 is connected in series with the output end of the corresponding comb filter 200, the gain values of the multiple gain amplifiers are different, and the output ends of the multiple gain amplifiers 201 are connected to the first Two adders 202 are connected;

A plurality of comb filters 200 and a plurality of gain amplifiers 201 are used for filtering and signal gain respectively on the first acoustic signal to obtain a plurality of delayed attenuated acoustic signals, the signal delays of the plurality of delayed attenuated acoustic signals Different from signal attenuation;

The second adder 202 is configured to add the multiple delayed attenuated acoustic signals to obtain the early reflected acoustic signals.

In the embodiment of the present application, an output end of each comb filter is connected to a gain amplifier, and the gain amplifier has different values, and different gain values can make the signal attenuation degrees of multiple delayed attenuated acoustic signals different.

In the embodiment of the present application, after a plurality of delayed attenuated acoustic signals are obtained, the signals of the multiple delayed attenuated acoustic signals are added to obtain an early reflected acoustic signal.

It can be understood that the early reflected sound circuit can be a left channel early reflected sound circuit or a right channel early reflected sound circuit, and correspondingly, the late reflected sound circuit can be a left channel late reflected sound circuit or a right channel. Late reflection sound circuit; the output end of the left channel early reflection sound circuit is connected with the left channel late reflection sound circuit; the output end of the right channel early reflection sound circuit is connected with the right channel late reflection sound circuit circuit connection.

In the embodiment of the present application, the first sound signal is passed through the left channel early reflected sound circuit and the left channel late reflected sound circuit to obtain the left channel late reflected sound signal; the first sound signal is passed through the right channel early reflected sound circuit and the right channel. The post reflection sound circuit of the channel obtains the post reflection sound signal of the right channel.

In the embodiment of the present application, the delay and gain values of the all-pass filter and the comb filter in the sound field expansion circuit are asymmetric and independently adjustable, which is more in line with the spatial information of the real sound field heard by the left and right ears.

Based on the above embodiment, the embodiment of the present application further provides an electronic device 6. As shown in FIG. 6, the electronic device 6 includes: a left channel input end 60, a right channel input end 61, a sound field preprocessing circuit 62, The left channel sound field expansion circuit 63, the right channel sound field expansion circuit 64, the left channel output circuit 65 and the right channel output circuit 66, the left channel sound field expansion circuit 63 and the right channel sound field expansion circuit 64 and the The sound field expansion circuit described in any one of the above is the same; wherein,

The left channel input terminal 60 and the right channel input terminal 61 are respectively connected with the input terminal of the sound field preprocessing circuit 62, and the output terminal of the sound field preprocessing circuit 62 is respectively connected with the left channel sound field expansion. The input end of the circuit 63 is connected to the input end of the right channel sound field expansion circuit 64, and the output end of the left channel sound field expansion circuit 63 and the left channel input end 60 are respectively connected with the left channel output circuit. 65, the output end of the right channel sound field expansion circuit 64 and the right channel input end 61 are respectively connected with the input end of the right channel output circuit 66;

The left channel input terminal is used for inputting the left channel input sound signal, and the right channel input terminal is used for inputting the right channel input sound signal;

the acoustic signal preprocessing circuit, configured to preprocess the left channel input signal and the right channel input signal to obtain the first acoustic signal;

The left channel sound field expansion circuit is used for processing the first sound signal to obtain the left channel late reflection sound signal;

The left channel output circuit is configured to process (for example, signal addition) the left channel input sound signal and the left channel late reflection sound signal to obtain the left channel output sound signal;

The right channel sound field expansion circuit is used for processing the first sound signal to obtain the right channel late reflected sound signal;

The right channel output circuit is configured to process the right channel input sound signal and the right channel post-reflection sound signal (eg, perform signal addition) to obtain a right channel output sound signal.

In the embodiment of the present application, the left channel sound field expansion circuit includes a left channel early reflected sound circuit and a left channel late reflected sound circuit, and the right channel sound field expansion circuit includes a right channel early reflected sound circuit and a right channel late reflected sound circuit The output end of the left channel early reflected sound circuit is connected with the input end of the left channel late reflected sound circuit; the output end of the right channel early reflected sound circuit is connected with the input end of the right channel late reflected sound circuit.

It should be noted that the early reflection sound circuit of the left channel and the early reflection sound circuit of the right channel are the same as the early reflection sound circuit described in any of the above, and the late reflection sound circuit of the left channel and the late reflection sound circuit of the right channel are the same as The post-reflection sound circuit described in any of the above is the same.

In the embodiment of the present application, the acoustic signal preprocessing circuit includes an adder-subtractor and a gain amplifier, and the acoustic signal preprocessing circuit uses the adder-subtractor to perform an addition or subtraction operation on the left channel input acoustic signal and the right channel input acoustic signal, Then, the reduction operation is performed through the gain to obtain the first sound signal.

In the embodiment of the present application, the Bluetooth chip inputs the left channel input sound signal to the sound signal preprocessing circuit through the left channel input port, inputs the left channel input sound signal through the left channel sound field expansion circuit, and inputs the left channel input sound signal through the right channel input port to the sound signal preprocessing circuit. The right channel sound field expansion circuit inputs the right channel input sound signal. When the left channel late reflection sound signal outputs the left channel late reflection sound signal, the left channel output sound signal adds the left channel input sound signal and the left channel late reflection sound signal to obtain the left channel output sound signal. signal; when the right channel late reflected sound signal outputs the right channel late reflected sound signal, the right channel output sound signal adds the right channel input sound signal and the right channel late reflected sound signal to obtain the right channel Output an acoustic signal.

In the embodiment of the present application, the electronic device further includes: a communication module, a left channel speaker and a right channel speaker; the communication module is connected to the left channel input end and the right channel input end, and the output end of the left channel output circuit is connected to the right channel input end. The output end of the channel output circuit is connected to the speaker; the communication module is used to receive audio data and separate the audio data into the left channel input sound signal and the right channel input sound signal; the left channel speaker is used to play the left channel The right channel speaker is used to play the output sound signal of the right channel.

Exemplarily, the schematic diagram of the structure of the electronic device is shown in FIG. 7, including a left channel input end 701, a right channel input end 702, an adder-subtractor 703, a gain amplifier 704, a left channel early reflected sound circuit 705, a left channel The post-channel reflected sound circuit 706, the left channel output circuit 707, the right channel early reflected sound circuit 708, the right channel late reflected sound circuit 709, and the right channel output circuit 7010.

As shown in Figure 7, for the left channel. The left channel early reflected sound circuit 705 is composed of a comb filter 7051, a comb filter 7052, a comb filter 7053, a comb filter 7054, a comb filter 7055, and a comb filter 7056 in parallel, wherein, The output end of comb filter 7051 is connected to gain amplifier 7057, the output end of comb filter 7052 is connected to gain amplifier 7058, the output end of comb filter 7053 is connected to gain amplifier 7059, the output end of comb filter 7054 is connected to gain amplifier 70510, and the comb filter 7054 output end is connected to gain amplifier 70510. The output end of the filter 7055 is connected to the gain amplifier 70511, the output end of the comb filter 7056 is connected to the gain amplifier 70512, the output ends of the gain amplifier 7057, the gain amplifier 7058, the gain amplifier 7059, the gain amplifier 70510, the gain amplifier 70511, and the gain amplifier 70512 are connected An adder 70513, gain amplifier 7057, gain amplifier 7058, gain amplifier 7059, gain amplifier 70510, gain amplifier 70511, gain amplifier 70512 have different values; 7062, an all-pass filter 7063, an all-pass filter 7064, and an all-pass filter 7065 are connected in series, and the output end of the all-pass filter 7065 is also connected to an IIR low-pass filter 7066 and a feedback gain amplifier 7067, wherein the IIR low-pass The filter 7066 is composed of a delay device 70661, a gain amplifier 70662 and an adder 70663. The input end of the adder 7061 is respectively connected to the output end of the adder 70513 and the output end of the feedback gain amplifier 7067, and the input end of the feedback gain amplifier 7067 is respectively It is connected to the input end of the delayer 70662 and the output end of the adder 70663. The input end of the adder 70663 is connected to the output end of the all-pass filter 7065 and the output end of the delayer 70661 respectively. The input end of the delayer 70661 It is connected with the output end of the gain amplifier 70662; the left channel output circuit 707 is composed of the adder 7071 and the left channel output end 7072, and the input end of the adder 7071 is respectively connected with the output end of the all-pass filter 7065 and the left channel input end 701 is connected, and the output end of the adder 7071 is connected to the left channel output end 7072.

As shown in Figure 7, for the right channel. The right channel early reflected sound circuit 708 is composed of a comb filter 7081, a comb filter 7082, a comb filter 7083, a comb filter 7084, a comb filter 7085, and a comb filter 7086 in parallel, wherein, The output end of comb filter 7081 is connected to gain amplifier 7087, the output end of comb filter 7082 is connected to gain amplifier 7088, the output end of comb filter 7083 is connected to gain amplifier 7089, the output end of comb filter 7084 is connected to gain amplifier 70810, The output end of filter 7085 is connected to the output end of gain amplifier 70811, the output end of comb filter 7086 is connected to gain amplifier 70812, gain amplifier 7087, gain amplifier 7088, gain amplifier 7089, gain amplifier 70810, gain amplifier 70811, gain amplifier 70812 An adder 70813 is connected to the output end of the amplifier. The values of gain amplifier 7087, gain amplifier 7088, gain amplifier 7089, gain amplifier 70810, gain amplifier 70811 and gain amplifier 70812 are different; All-pass filter 7092, all-pass filter 7093, all-pass filter 7094, and all-pass filter 7095 are connected in series, and the output end of all-pass filter 7095 is also connected to IIR low-pass filter 7096 and feedback gain amplifier 7097, wherein , the IIR low-pass filter 7066 is composed of a delayer 70961, a gain amplifier 70962 and an adder 70963. The input end of the adder 7091 is respectively connected to the output end of the adder 70913 and the output end of the feedback gain amplifier 7097. The feedback gain amplifier 7097 The input terminals of the gain amplifier 70962 are respectively connected to the input terminal of the gain amplifier 70962 and the output terminal of the adder 70963. The input terminals of the adder 70963 are respectively connected to the output terminal of the all-pass filter 7095 and the output terminal of the delay device 70961. The delay device 70961 The input end is connected with the output end of the gain amplifier 70962; the right channel output circuit 7010 is composed of the adder 70101 and the right channel output end 70102, the input end of the adder 70101 is respectively connected with the output end of the all-pass filter 7095 and the right channel output end 70102. The channel input terminal 702 is connected, and the output terminal of the adder 70101 is connected to the right channel output terminal 70102.

The signal flow corresponding to FIG. 7 is: the left channel input sound signal input from the left channel input terminal 701 and the right channel input sound signal input from the right channel input terminal 702 pass through the adder-subtractor 703 and the gain amplifier 704. Addition or signal subtraction and reduction processing to obtain the first sound signal, the first sound signal is passed through the left channel early reflection sound circuit 705 to obtain the left channel early reflection sound signal of the simulated sound field, and the left channel early reflection sound signal is passed through the left channel. The late reflection sound circuit 706 obtains the late reflection sound of the left channel, and the late reflection sound of the left channel and the input sound signal of the left channel are added by the left channel output circuit 707 to obtain the output sound signal of the left channel; The sound signal passes through the right channel early reflection sound circuit 708 to obtain the right channel early reflection sound signal of the simulated sound field, and the right channel early reflection sound signal passes through the right channel late reflection sound circuit 709 to obtain the right channel late reflection sound, and the right channel The later reflected sound and the input sound signal of the right channel are added by the right channel output circuit 7010 to obtain the output sound signal of the right channel.

It can be understood that the early reflected sound circuit of the sound field expansion circuit is composed of multiple comb filters in parallel, and the later reflected sound circuit is composed of multiple all-pass filters connected in series. The stereo sound field expansion can be realized by connecting multiple all-pass filters in series. Since the comb filter and the all-pass filter mainly implement multiplication and addition operations, the multiplication and addition operations in the Bluetooth chip can usually be performed within one clock cycle. Completed, thereby reducing the amount of operation of the stereo sound field expansion and the power consumption of the headset.

An embodiment of the present application provides a sound field expansion method, as shown in FIG. 8 , which is applied to the sound field expansion circuit shown in the above-mentioned embodiment, and the sound field expansion circuit includes: an early reflection sound circuit composed of a plurality of comb filters connected in parallel and a late-stage reflected sound circuit connected to the output end of the early-stage reflected sound circuit, the late-stage reflected sound circuit is composed of multiple all-pass filters connected in series, and the method may include:

S101. Preprocess the input acoustic signal to obtain a first acoustic signal.

The sound field expansion method provided by the embodiment of the present application is suitable for a scenario where a stereo sound field is expanded when a stereo signal is played.

In the embodiment of the present application, the sound field expansion circuit performs signal addition, signal subtraction, and reduction operations on the left channel input sound signal and the right channel input sound signal to obtain the first sound signal.

S102 , using a plurality of comb filters to filter the first acoustic signal respectively to obtain an early reflected acoustic signal.

After the sound field expansion circuit preprocesses the left channel input sound signal and the right channel input sound signal to obtain the first sound signal, the sound field expansion circuit uses a plurality of comb filters to filter the first sound signal respectively to obtain the early reflection sound signal.

In the embodiment of the present application, the early reflected sound circuit includes a left channel early reflected sound circuit and a right channel early reflected sound circuit, wherein the left channel early reflected sound circuit is composed of multiple parallel comb filters, and the right channel Early reflected acoustic circuits consisted of multiple comb filters connected in parallel.

In the embodiment of the present application, the first acoustic signal is input to the left channel early reflected acoustic circuit, and the first acoustic signal is filtered by a plurality of parallel comb filters to obtain the left channel early reflected acoustic signal.

Specifically, for the left channel early reflection sound circuit, the sound field expansion circuit uses a plurality of comb filters of the left channel early reflection sound circuit to filter the first sound signal respectively to obtain a plurality of delayed attenuated sound signals, The signal delay and signal attenuation of the multiple delayed attenuated sound signals are different; the sound field expansion circuit adds the multiple delayed attenuated sound signals to obtain the early reflection sound signal of the left channel.

In the embodiment of the present application, the first acoustic signal is input to the early reflected sound circuit of the right channel, and the first acoustic signal is filtered by a plurality of comb filters in parallel to obtain the early reflected sound signal of the right channel.

Specifically, for the early reflection sound circuit of the right channel, the sound field expansion circuit uses multiple comb filters of the early reflection sound circuit of the right channel to filter the first sound signal respectively to obtain a plurality of delayed attenuated sound signals, The signal delay and signal attenuation of the multiple delayed attenuated sound signals are different; the sound field expansion circuit adds the multiple delayed attenuated sound signals to obtain the early reflected sound signal of the right channel.

S103 , using a plurality of all-pass filters to phase shift the first input signal to obtain a later reflected sound signal, where the first input signal is an early reflected sound signal or obtained according to an early reflected sound signal.

When the sound field expansion circuit uses multiple comb filters to filter the first sound signal respectively to obtain the early reflected sound signal, the sound field expansion circuit uses multiple all-pass filters to phase shift the first input signal to obtain the later reflected sound signal, wherein the first input signal is an early reflected sound signal or is obtained according to an early reflected sound signal.

In the embodiment of the present application, the late reflected sound circuit includes a left channel late reflected sound circuit and a right channel late reflected sound circuit, wherein the left channel late reflected sound circuit is composed of a plurality of series-connected all-pass filters, and the right channel The late reflected sound circuit is composed of multiple all-pass filters connected in series. The output end of the left channel early reflected sound circuit is connected to the left channel late reflected sound circuit, and the right channel early reflected sound circuit is connected to the right channel late reflected sound circuit. connect.

In the embodiment of the present application, the left channel early reflected sound signal is input to the left channel late reflected sound circuit, and a plurality of series-connected all-pass filters are used to shift the phase of the left channel early reflected sound signal to obtain the left channel late reflected sound Signal.

Specifically, for the left channel late reflection sound circuit, the sound field expansion circuit uses multiple all-pass filters of the left channel late reflection sound circuit to shift the phase of the left channel early reflection sound signal to obtain the left channel late reflection sound. sound signal.

In the embodiment of the present application, the early reflected sound signal of the right channel is input to the late reflected sound circuit of the right channel, and the early reflected sound signal of the right channel is phase-shifted by a plurality of series-connected all-pass filters to obtain the late reflected sound of the right channel Signal.

Specifically, for the late reflection sound circuit of the right channel, the sound field expansion circuit uses multiple all-pass filters of the late reflection sound circuit of the right channel to shift the phase of the early reflection sound signal of the right channel to obtain the late reflection sound of the right channel. sound signal.

Further, after obtaining the late reflected sound signal, the sound field expansion circuit performs filtering and sound control on the late reflected sound signal to obtain a feedback signal; after that, the sound field expansion circuit adds the feedback signal and the early reflected sound signal to obtain the first signal. Input signal; use multiple all-pass filters to phase shift the first input signal to obtain a late reflected sound signal, wherein the reflected sound density corresponding to the late reflected sound signal obtained based on the feedback signal and the early reflected sound signal is greater than that based on the early reflected sound signal. The reflected sound density corresponding to the later reflected sound signal obtained from the reflected sound signal.

It should be noted that, for the left channel late-stage reflected sound signal and the right-channel late-stage reflected sound signal, the process of obtaining the late-stage reflected sound signal by the sound field expansion circuit is the same, which will not be repeated here.

S104: Obtain an output acoustic signal corresponding to the input acoustic signal corresponding to the input acoustic signal of the left channel according to the input acoustic signal and the later reflected acoustic signal.

After the sound field expansion circuit obtains the late reflected sound signal, the sound field expansion circuit obtains the left channel output sound signal corresponding to the left channel input sound signal according to the left channel input sound signal, the right channel input sound signal and the late reflected sound signal The right channel output sound signal corresponding to the right channel input sound signal.

Specifically, the sound field expansion circuit adds the left channel input sound signal and the corresponding left channel late reflection sound signal to obtain the left channel output sound signal; the sound field expansion circuit adds the right channel input sound signal and the corresponding right channel sound signal. The reflected sound signal in the later stage of the channel is added to obtain the output sound signal of the right channel.

It can be understood that the early reflected sound circuit of the sound field expansion circuit is composed of multiple comb filters in parallel, and the later reflected sound circuit is composed of multiple all-pass filters connected in series. The stereo sound field expansion can be realized by connecting multiple all-pass filters in series. Since the comb filter and the all-pass filter mainly implement multiplication and addition operations, the multiplication and addition operations in the Bluetooth chip can usually be performed within one clock cycle. Completed, thereby reducing the amount of operation of the stereo sound field expansion and the power consumption of the headset.

FIG. 9 is a second schematic diagram of the composition and structure of an electronic device 9 provided by an embodiment of the present application. In practical applications, based on the same disclosed concept of the above-mentioned embodiment, as shown in FIG. 9 , the electronic device 9 of this embodiment includes: Processor 901 , memory 902 and communication bus 903 .

In the process of a specific embodiment, the above-mentioned processor 901 may be an application specific integrated circuit (ASIC, Application Specific Integrated Circuit), a digital signal processor (DSP, Digital Signal Processor), a digital signal processing image processing circuit (DSPD, Digital Signal Processing Device), Programmable Logic Image Processing Circuit (PLD, Programmable Logic Device), Field Programmable Gate Array (FPGA, Field Programmable Gate Array), at least one of CPU, controller, microcontroller, microprocessor . It can be understood that, for different devices, the electronic device used to implement the function of the processor may also be other, which is not specifically limited in this embodiment.

In the embodiment of the present application, the above-mentioned communication bus 903 is used to realize the connection communication between the processor 901 and the memory 902; when the above-mentioned processor 901 executes the running program stored in the memory 902, the following sound field expansion method is implemented:

Preprocessing the input acoustic signal to obtain a first acoustic signal; using the multiple comb filters to filter the first acoustic signal respectively to obtain an early reflected acoustic signal; using the multiple all-pass filters to filter the first input acoustic signal The signal is phase-shifted to obtain a later reflected acoustic signal; according to the input acoustic signal and the later reflected acoustic signal, an output acoustic signal corresponding to the input acoustic signal is obtained, wherein the first input signal is the early reflection The acoustic signal may be obtained from the early reflected acoustic signal.

It can be understood that the above processor 901 is further configured to filter the first acoustic signal by using the multiple comb filters to obtain multiple delayed attenuated acoustic signals, the multiple delayed attenuated acoustic signals. The delay and signal attenuation are different; the multiple delayed attenuated acoustic signals are added to obtain the early reflected acoustic signal.

It can be understood that the above-mentioned processor 901 is also used to filter and soundly control the late reflected sound signal to obtain a feedback signal; and add the feedback signal and the early reflected sound signal to obtain the first reflected sound signal. an input signal; using the plurality of all-pass filters to phase-shift the first input signal to obtain the later reflected sound signal.

An embodiment of the present application provides a storage medium on which a computer program is stored, the computer-readable storage medium stores one or more programs, and the one or more programs can be executed by one or more processors, and is applied to electronic In the device, the computer program implements the sound field expansion method as described above.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

From the description of the above embodiments, those skilled in the art can clearly understand that the method of the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is better implementation. Based on this understanding, the technical solutions of the present disclosure can be embodied in the form of software products in essence or the parts that make contributions to related technologies. The computer software products are stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) ), including several instructions for causing an image display device (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in the various embodiments of the present disclosure.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the protection scope of the present application.

Claims (20)

1. A sound field expansion circuit, the sound field expansion circuit comprises: an early reflected sound circuit and a late reflected sound circuit;

   The early reflected sound circuit includes a plurality of comb filters connected in parallel, and the gains of the plurality of comb filters are different;

   The late reflected sound circuit is connected to the output end of the early reflected sound circuit, the late reflected sound circuit includes an all-pass filter circuit, and the all-pass filter circuit includes a plurality of all-pass filters connected in series;

   The early reflected sound circuit is used to filter the first sound signal by using the plurality of comb filters to obtain the early reflected sound signal, and the first sound signal is obtained according to the input sound signal;

   The late-stage reflected sound circuit is used to phase-shift the first input signal by using the plurality of all-pass filters to obtain a late-stage reflected sound signal, so as to obtain an output according to the input sound signal and the late-stage reflected sound signal An acoustic signal, wherein the first input signal is the early reflected acoustic signal or is obtained from the early reflected acoustic signal.
2. The circuit according to claim 1, wherein the late reflected sound circuit further comprises: a first adder and a low-pass feedback circuit; the first input end of the first adder and the output of the early reflected sound circuit The second input end of the first adder is connected to the output end of the low-pass feedback circuit, the output end of the first adder is connected to the input end of the all-pass filter circuit, and the The output end of the all-pass filter circuit is connected with the input end of the low-pass feedback circuit;

   The low-pass feedback circuit is used to filter and control the sound of the later reflected sound signal to obtain a feedback signal, and transmit the feedback signal to the second input end of the first adder;

   the first adder, configured to add the feedback signal and the early reflected sound signal to obtain the first input signal;

   The plurality of all-pass filters are also used for phase-shifting the first input signal to obtain the later reflected sound signal.
3. The circuit according to claim 2, wherein the low-pass feedback circuit comprises a low-pass filter and a feedback gain amplifier, the input terminal of the low-pass filter is connected to the output terminal of the plurality of all-pass filters, The output end of the low-pass filter is connected to the input end of the feedback gain amplifier, and the output end of the feedback gain amplifier is connected to the second input end of the first adder;

   The low-pass filter is used to filter the late-stage reflected acoustic signal to obtain a first filtered acoustic signal, wherein the high-frequency sound attenuation of the first filtered acoustic signal is greater than the low-frequency sound attenuation;

   The feedback gain amplifier is used for performing sound control on the first filtered sound signal to obtain the feedback signal.
4. The circuit according to claim 1, wherein the early reflected sound circuit further comprises: a plurality of gain amplifiers and a second adder, the plurality of gain amplifiers and the plurality of comb filters are in one-to-one correspondence, each The input ends of one gain amplifier are respectively connected in series with the output ends of the corresponding comb filters, the gain values of the multiple gain amplifiers are different, and the output ends of the multiple gain amplifiers are connected to the second adder;

   The plurality of comb filters and the plurality of gain amplifiers are used for filtering and signal gain respectively for the first acoustic signal to obtain a plurality of delayed attenuated acoustic signals, the plurality of delayed attenuated acoustic signals The signal delay and signal attenuation are different;

   The second adder is configured to add the plurality of delayed attenuated acoustic signals to obtain the early reflected acoustic signals.
5. The circuit according to any one of claims 1-4, wherein the signal delay of the comb filter is greater than the signal delay of the all-pass filter.
6. The circuit of claim 1, wherein the comb filter includes a third summer, a first delay, a first feedback gain amplifier, and a first low-pass filter, wherein the first low-pass The filter consists of a second delayer, a first gain amplifier and a fourth adder;

   The first input end of the third adder is connected to the input of the comb filter, the output end of the first adder is connected to the input end of the first delay device, and the output end of the first delay device is connected to the input end of the first delay device. The output end is connected to the output end of the comb filter and the first input end of the fourth adder, the second input end of the fourth adder is connected to the output end of the first gain amplifier, and the second input end of the fourth adder is connected to the output end of the first gain amplifier. The input end of a gain amplifier is connected to the output end of the second delay device, the input end of the second delay device and the output end of the fourth adder are connected to the input end of the first feedback gain amplifier, The output terminal of the first feedback gain amplifier is connected to the second input terminal of the third adder.
7. The circuit of claim 1, wherein the all-pass filter comprises: a fifth adder, a third delay, a sixth adder, a second gain amplifier, a third gain amplifier, and a second feedback gain amplifier ;

   The first input end of the fifth adder is connected to the input of the all-pass filter, and the output end of the fifth adder is respectively connected to the input end of the third delayer and the output end of the second gain amplifier. input end, the output end of the third delay device is respectively connected to the input end of the third gain amplifier and the input end of the second feedback gain amplifier, the output end of the third gain amplifier and the second gain amplifier The output end is connected to the input end of the sixth adder, the output end of the second feedback gain amplifier is connected to the second input end of the fifth adder, and the output end of the sixth adder is connected to the all-pass filter output of the device.
8. The circuit of claim 3 or 6, wherein the low-pass filter is a wireless impulse response IIR low-pass filter.
9. An electronic device comprising: a left channel input end, a right channel input end, a sound field preprocessing circuit, a left channel sound field expansion circuit, a right channel sound field expansion circuit, a left channel output circuit and a right channel channel output circuit, the left channel sound field expansion circuit and the right channel sound field expansion circuit are the same as the circuit described in any one of claims 1-8; wherein,

   The left channel input terminal and the right channel input terminal are respectively connected with the input terminal of the sound field preprocessing circuit, and the output terminal of the sound field preprocessing circuit is respectively connected with the input terminal of the left channel sound field expansion circuit. It is connected with the input end of the right channel sound field expansion circuit, the output end of the left channel sound field expansion circuit and the left channel input end are respectively connected with the input end of the left channel output circuit, and the right channel sound field expansion circuit is connected with the input end of the left channel output circuit. The output end of the channel sound field expansion circuit and the right channel input end are respectively connected with the input end of the right channel output circuit;

   The left channel input terminal is used for inputting the left channel input sound signal, and the right channel input terminal is used for inputting the right channel input sound signal;

   the acoustic signal preprocessing circuit, configured to preprocess the left channel input signal and the right channel input signal to obtain the first acoustic signal;

   The left channel sound field expansion circuit is used for processing the first sound signal to obtain the left channel late reflection sound signal;

   The left channel output circuit is used for processing the left channel input sound signal and the left channel late reflection sound signal to obtain the left channel output sound signal;

   The right channel sound field expansion circuit is used for processing the first sound signal to obtain the right channel late reflected sound signal;

   The right channel output circuit is used for processing the right channel input sound signal and the right channel post-reflection sound signal to obtain a right channel output sound signal.
10. The electronic device according to claim 9, wherein the left channel sound field expansion circuit comprises a left channel early reflection sound circuit and a left channel late reflection sound circuit, and the right channel sound field expansion circuit comprises a right channel early reflection sound circuit A reflected sound circuit and a right channel late reflected sound circuit, wherein the left channel early reflected sound circuit and the right channel early reflected sound circuit are the same as the early reflected sound circuit described in any one of claims 1-8 ; Described left channel late stage reflected sound circuit and described right channel late stage reflected sound circuit are identical with the late stage reflected sound circuit described in any one of claims 1-8;

    The output end of the left channel early reflected sound circuit is connected with the input end of the left channel late reflected sound circuit; the output end of the right channel early reflected sound circuit is connected to the output end of the right channel late reflected sound circuit. input connection.
11. The electronic device according to claim 9, wherein the electronic device further comprises: a communication module, a left channel speaker and a right channel speaker; the communication module is connected to the left channel input terminal and the right channel the input end is connected, the output end of the left channel output circuit is connected with the left channel speaker, and the output end of the right channel output circuit is connected with the right channel speaker;

    the communication module for receiving audio data and separating the audio data into the left channel input sound signal and the right channel input sound signal;

    The left channel speaker is used for playing the left channel output sound signal, and the right channel speaker is used for playing the right channel output sound signal.
12. A sound field expansion method, applied to the sound field expansion circuit, the sound field expansion circuit comprising: an early reflection sound circuit composed of a plurality of comb filters connected in parallel and a late reflection sound circuit connected to an output end of the early reflection sound circuit The acoustic circuit, the late reflected acoustic circuit is composed of a plurality of all-pass filters connected in series, and the method further includes:

    Preprocessing the input acoustic signal to obtain a first acoustic signal;

    Filter the first acoustic signal by using the plurality of comb filters to obtain an early reflected acoustic signal;

    Phase-shift the first input signal by using the plurality of all-pass filters to obtain a later reflected sound signal, wherein the first input signal is the early reflected sound signal or obtained according to the early reflected sound signal;

    According to the input acoustic signal and the later reflected acoustic signal, an output acoustic signal corresponding to the input acoustic signal is obtained.
13. The method according to claim 12, wherein, the described utilizing a plurality of comb filters to filter the first acoustic signal respectively to obtain an early reflected acoustic signal, comprising:

    Using the plurality of comb filters to filter the first acoustic signal, respectively, to obtain a plurality of time-delayed attenuated acoustic signals, the signal delay and signal attenuation of the plurality of time-delayed attenuated acoustic signals are different;

    The multiple delayed attenuated acoustic signals are added to obtain the early reflected acoustic signals.
14. The method according to claim 12, wherein the phase-shifting the first input signal by using a plurality of all-pass filters to obtain a later reflected acoustic signal comprises:

    Perform filtering and sound control on the later reflected sound signal to obtain a feedback signal;

    adding the feedback signal and the early reflected sound signal to obtain the first input signal;

    Using the plurality of all-pass filters, phase-shift the first input signal to obtain the late-stage reflected acoustic signal.
15. The method according to claim 12, wherein the input sound signal comprises: a left channel input sound signal and a right channel input sound signal; the preprocessing of the input sound signal to obtain the first sound signal comprises:

    The first sound signal is obtained by performing signal addition or signal subtraction and reduction operations on the left channel input sound signal and the right channel input sound signal.
16. An electronic device, the electronic device comprises: a processor, a memory and a communication bus; the processor executes the following method when executing a running program stored in the memory:

    Preprocessing the input acoustic signal to obtain a first acoustic signal;

    Filter the first acoustic signal by using the plurality of comb filters to obtain an early reflected acoustic signal;

    Phase-shift the first input signal by using the plurality of all-pass filters to obtain a later reflected sound signal, wherein the first input signal is the early reflected sound signal or obtained according to the early reflected sound signal;

    According to the input acoustic signal and the later reflected acoustic signal, an output acoustic signal corresponding to the input acoustic signal is obtained.
17. The electronic device of claim 16, wherein,

    The processor is further configured to filter the first acoustic signal by using the multiple comb filters to obtain multiple delayed attenuated acoustic signals, the signal delay sum of the multiple delayed attenuated acoustic signals The attenuation is different; the multiple delayed attenuated acoustic signals are added to obtain the early reflected acoustic signal.
18. The electronic device of claim 16, wherein,

    The processor is further configured to filter and soundly control the late reflected sound signal to obtain a feedback signal; and add the feedback signal and the early reflected sound signal to obtain the first input signal; The first input signal is phase-shifted by using the plurality of all-pass filters to obtain the later reflected acoustic signal.
19. The electronic device according to claim 16, wherein the input acoustic signal comprises: a left channel input acoustic signal and a right channel input acoustic signal;

    The processor is further configured to perform signal addition or signal subtraction and reduction operations on the left channel input sound signal and the right channel input sound signal to obtain the first sound signal.
20. A storage medium having a computer program stored thereon, the computer program implementing the method according to any one of claims 12-15 when executed by a processor.

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