Method And Device For Reducing Voice Reverberation Based On Double Microphones

摘要

The invention discloses a method and a device for reducing voice reverberation based on double microphones. The method comprises the steps of calculating a transfer function h(t) from a secondary microphone to a primary microphone according to an input signal x2(t) of the primary microphone and an input signal x1(t) of the secondary microphone; judging the strength of reverberation according to h(t) and calculating a regulatory factor β of a gain function by taking a tail section hr(t) of the h(t); obtaining a late reverberation estimation signal {circumflex over (r)}(t) of x2(t) with the convolution of x1(t) and hr(t); calculating the gain function according to the frequency spectrum of x2(t), β and frequency spectrum of {circumflex over (r)}(t); obtaining the reverberation removed frequency spectrum of x2(t) by multiplying the frequency spectrum of x2(t) by the gain function; and obtaining a late reverberation removed time-domain signal of x2(t) by frequency-time conversion. Thus, the late reverberation can be removed from the input signal of the primary microphone, early reverberation can be preserved, processed voice is not caused to be thin, and the voice quality is improved. Meanwhile, spectral subtraction intensity is adjusted according to the strength of the reverberation so as to ensure that the voice is not damaged on the condition that the reverberation is weak and the voice intelligibility is originally high. Accurate estimation of DOA of direct sound is not needed, and therefore the microphones are not required to have high consistency.

主权项

1. A method for reducing voice reverberation based on double microphones, characterized in that the method comprises:
receiving a primary microphone input signal and a secondary microphone input signal, which are processed frame-by-frame as follows: calculating a transfer function h(t) from the secondary microphone to the primary microphone according to the primary microphone input signal and the secondary microphone input signal; obtaining a tail section hr(t) of the transfer function h(t), judging the strength of reverberation according to the transfer function h(t) and calculating a regulatory factor β of a gain function; obtaining a late reverberation estimation signal of the primary microphone input signal with the convolution of the secondary microphone input signal and hr(t); converting the late reverberation estimation signal of the primary microphone input signal from time domain to frequency domain to obtain a late reverberation spectrum of the primary microphone input signal; converting the primary microphone input signal from time domain to frequency domain to obtain a frequency spectrum of the primary microphone input signal; calculating the gain function according to the frequency spectrum of the primary microphone input signal, the regulatory factor β of the gain function and the late reverberation spectrum of the primary microphone input signal; using the frequency spectrum of the primary microphone input signal to multiply by the gain function to obtain a reverberation-removed frequency spectrum of the primary microphone input signal; converting the reverberation-removed frequency spectrum of the primary microphone input signal from frequency domain to time domain to obtain a reverberation-removed time domain signal of the primary microphone input signal; outputting a reverberation-removed continuous signal of the primary microphone input signal after frame-by-frame overlapping and summing the reverberation-removed time domain signal of the primary microphone input signal.