- Rita Singh, K. Kumatani, J. McDonough, Chen Liu. 2012. A signal-separation-based array postfilter for distant speech recognition. Abstract: In standard microphone array processing for distant speech recognition, the beamformed output is postﬁltered to reduce residual noise. Postﬁltering is usually performed through a Weiner ﬁlter whose parameters are estimated from both the beamformer output and the signals captured at the microphones themselves. Conventional postﬁltering methods assume diffuse or incoherent noise at the various microphones in order to estimate these parameters. When the noise does not conform to this assumption they perform poorly. We propose an alternate postﬁltering mechanism that attenuates noise by estimating and separating out the contributions of speech and noise explicitly. Experiments on a corpus of in-car two-channel recordings show that the proposed postﬁltering algorithm outperforms conventional postﬁlters signiﬁcantly under many noise conditions.
