This paper addresses issues in improving hands-free speech recognition performance in car
environments. A three-microphone array has been used to form a beamformer with leastmean
squares (LMS) to improve Signal to Noise Ratio (SNR). A three-microphone array
has been paralleled to a Voice Activity Detection (VAD). The VAD uses time-delay
estimation together with magnitude-squared coherence (MSC).
Qr, Z., Moir, T.J. (2005), Automotive three-microphone voice activity detector and noise-canceller, Research Letters in the Information and Mathematical Sciences, 7, 147-155