Howling suppression method based on feedback signal spectrum estimation

Abstract

The invention relates to a howling suppression method based on feedback signal spectrum estimation. The method comprises the following steps: firstly, carrying out framing, windowing and Fourier transform on a signal collected by a microphone and a loudspeaker output signal respectively so as to obtain a corresponding frequency domain signal; then, according to the microphone frequency domain signal and the loudspeaker output frequency domain signal, calculating a cross-power spectrum between the microphone and the loudspeaker output signal and a power spectrum of the loudspeaker output signal; dividing the cross-power spectrum by the power spectrum so as to obtain estimation of a feedback path transfer function amplitude spectrum; using the obtained estimation of the feedback path transfer function spectrum amplitude to calculate a current frame feedback signal amplitude spectrum; and then using the microphone signal amplitude spectrum and the obtained feedback signal amplitude spectrum to calculate a gain function; finally, according to the obtained gain function, carrying out correction on the microphone frequency domain signal so as to realize howling suppression. By using the method of the invention, convergence and tracking speeds are fast, robustness is good and algorithm complexity is low, which is good for real-time realization.

Description

technical field [0001] The invention relates to the field of howling suppression, in particular to a howling suppression method based on feedback signal frequency spectrum estimation. Background technique [0002] Howling suppression is also called "acoustic feedback suppression", "acoustic feedback control", "feedback elimination" and so on in some literatures, and they express the same meaning. like figure 1 as shown, figure 1 Generate a schematic for howling. s(n) represents the near-end voice, which is a signal that needs to be amplified; d(n) represents the sound emitted from the speaker and fed back to the microphone through the feedback path 102, and the feedback signal picked up by the microphone. d(n) is not the desired signal and needs to be suppressed. The forward processing module 104 is used to complete functions such as howling suppression and automatic gain control. The transfer function between the input signal s(n) and the output signal y(n) is G(z) / (1-...

AI Technical Summary

Problems solved by technology

The main disadvantage of discontinuous howling suppression is that this method needs to interrupt the normal input speech signal, thereby affecting the intelligibility of the speech, so it is unacceptable in many occasions

Continuous howling suppression uses continuous input signals to estimate the feedback signal, but the convergence speed is very slow

[0008] To sum up, the current howling suppression method is not robust, and transient howling is likely to occur when the feedback path changes

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