Multichannel feature enhancement in distributed microphone arrays for robust distant speech recognition in smart rooms

Room reverberation and environmental noise present challenges for integration of speech recognition technology in smart room applications. We present a multichannel enhancement framework for distributed microphone arrays to mitigate the effects of both additive noise and reverberation on distant-talking microphones. The proposed approach uses techniques of nonnegative matrix and tensor factorization to achieve both noise suppression (through sparse representation of speech spectra) and dereverberation (through decomposition of magnitude spectra into convolutive components). Results of ASR experiments on the DIRHA-GRID corpus confirm that the proposed approach can achieve relative improvements of up to +20% in recognition accuracy in highly reverberant and noisy conditions using clean-trained models.