Robust Digit Recognition Using Phase-Dependent Time-Frequency Masking

A technique using the time-frequency phase information of two microphones is proposed to estimate an ideal timefrequency mask using time-delay-of-arrival (TDOA) of the signal of interest. At a signal-to-noise ratio (SNR) of 0dB, the proposed technique using two microphones achieves a digit recognition rate (average over 5 speakers, each speaking 20-30 digits) of 71%. In contrast, delayand-sum beamforming only achieves a 40 % recognition rate with two microphones and 60 % with four microphones. Superdirective beamforming achieves a 44 % recognition rate with two microphones and 65% with four microphones. 1