An approach to dereverberation using multi-microphone sub-band envelope estimation
H. Wang, Fumitada Itakura · 1991
An approach to recovering acoustically reverberated signals using multi-microphone subband envelope estimation (M-SBEE) is proposed. The invertibility of a subband signal depends on the zero distribution of the transfer function in the z-plane in that subband. In a multi-microphone system, the transfer functions between the sound source and the microphones have different zero distributions. This method takes advantage of the differences of the zero distributions by choosing the best invertible microphone in each subband, and reconstructing the full band signal using the best microphone in each subband. The recovered speech signals using seven microphones with 256 subbands are perfect when the reverberation time (RT) is less than 0.43 sec, and is satisfactory for even RT=1.07 sec.>