Coupling beamforming with spatial and spectral feature based spectral enhancement and its application to meeting recognition

This paper discusses microphone array based interference reduction approaches for robust automatic speech recognition. A model based multichannel spectral enhancement approach has recently been proposed for effectively reducing interference by exploiting both the spatial and spectral features of the signals. With the goal of further improving the effectiveness of this approach, we propose a new framework that combines this approach with a microphone-array based beamforming approach. Because the two approaches can work in a complementary manner in the proposed framework, they can greatly improve the interference reduction performance. We apply the proposed framework to the recognition of actual meetings, and show that it is superior to the use of beamforming or spectral enhancement alone in terms of the word error rates.