Method for reducing residual echo and electronic device using the same

1. A method for reducing residual echo, comprising the following steps of:

performing an echo cancellation process on a voice input signal according to an echo reference signal to obtain an echo cancellation signal;

performing a fast Fourier Transform (FFT) on the echo reference signal to obtain a reference spectrum signal for each frame;

performing the FFT on the echo cancellation signal to obtain a speech spectrum signal for each frame;

using the reference spectrum signal of a current frame and the speech spectrum signal of the current frame to obtain a priori signal-to-noise ratio of the current frame according to a principle of additive noise;

filtering the speech spectrum signal of the current frame by a Wiener filter coefficient of the current frame determined by the priori signal-to-noise ratio of the current frame to obtain a target spectrum signal of each frame; and

performing an inverse fast Fourier Transform (IFFT) on the target spectrum signal of each frame to obtain a target voice signal;

wherein the priori signal-to-noise ratio of the current frame is the ratio of the non-reference spectrum signal in the speech spectrum signal of the current frame to the reference spectrum signal of the current frame.

2. The method according to claim 1 , further comprising:

obtaining a voice reception signal received by an audio reception module of an electronic device; and

performing a first preprocessing procedure on the voice reception signal to obtain the voice input signal.

3. The method according to claim 2 , wherein the first preprocessing procedure comprises: performing beamforming and denoising processing on the voice reception signal.

4. The method according to claim 1 , further comprising:

collecting an audio analog signal output by a power amplifier circuit of an electronic device, and performing analog-to-digital conversion on the audio analog signal to obtain the echo reference signal, wherein the audio analog signal is played through a speaker of the electronic device.

5. The method according to claim 1 , further comprising:

performing a second preprocessing procedure on the target voice signal to obtain a voice output signal.

6. The method according to claim 5 , wherein the second preprocessing procedure comprises: performing beamforming and denoising processing on the target voice signal.

7. An electronic device, comprising:

a non-transitory computer-readable storage medium configured to store program code; and

one or more processors configured to execute the program code to:

perform an echo cancellation process on a voice input signal according to an echo reference signal to obtain an echo cancellation signal;

perform a fast Fourier Transform (FFT) on the echo reference signal to obtain a reference spectrum signal for each frame;

perform the FFT on the echo cancellation signal to obtain a speech spectrum signal for each frame;

use the reference spectrum signal of a current frame and the speech spectrum signal of the current frame to obtain a priori signal-to-noise ratio of the current frame according to a principle of additive noise;

filter the speech spectrum signal of the current frame by a Wiener filter coefficient of the current frame determined by the priori signal-to-noise ratio of the current frame to obtain a target spectrum signal of each frame; and

perform an inverse fast Fourier Transform (IFFT) on the target spectrum signal of each frame to obtain a target voice signal;

wherein the priori signal-to-noise ratio of the current frame is the ratio of the non-reference spectrum signal in the speech spectrum signal of the current frame to the reference spectrum signal of the current frame.

8. The electronic device according to claim 7 , wherein the electronic device further comprises:

a power amplifier circuit connected to the one or more processors and configured to output an audio analog signal;

a speaker connected to the power amplifier circuit and configured to play the audio analog signal; and

a recovery circuit connected to the power amplifier circuit and configured to collect the audio analog signal and perform analog-to-digital conversion on the audio analog signal to obtain the echo reference signal.

9. The electronic device according to claim 8 , wherein the electronic device further comprises:

a memory connected to the recovery circuit and the one or more processors and configured to store the echo reference signal.

10. The electronic device according to claim 7 , the electronic device further comprises an audio reception module configured to receive a voice reception signal, and the one or more processors are further configured to perform a first preprocessing procedure on the voice reception signal to obtain the voice input signal.

11. The electronic device according to claim 10 , wherein the one or more processors are further configured to perform beamforming and denoising processing on the voice reception signal to obtain the voice input signal.

12. The electronic device according to claim 7 , wherein the one or more processors are further configured to perform a second preprocessing procedure on the target voice signal to obtain a voice output signal.

13. The electronic device according to claim 12 , wherein the one or more processors are further configured to perform beamforming and denoising processing on the target voice signal to obtain the voice output signal.