International Workshop on Acoustic Echo and Noise Control (IWAENC 2010), Tel Aviv, Israel, August 2010.
In this paper the role of the blocking matrix is investigated in the context of microphone array postfilters. A generic stability criterion, which depends on the blocking matrix, is given and discussed. This allows a new view on the causes of postfilter instability. The performance of non-adaptive and adaptive blocking matrix implementations is investigated for a car environment. Finally, the impact of these matrices on the postfilter performance is analyzed. The results suggest, that an adaptive implementation of the blocking matrix is a way to substantially improve the speech quality delivered by the beamformer-postfilter system.Read/download now