A double-talk detector for acoustic echo cancellation applications

Abstract

In acoustic echo cancellation applications, the presence of near-end speech causes divergence of the adaptive filter which is used to model the echo path. A robust acoustic echo canceler is the one which is equipped with an algorithm that detects periods of double talk and puts the adaptive algorithm into a double-talk handling mode. This paper proposes a double-talk detector based on an angle measure between two vectors comprising samples of input signal to the near-end microphone and the estimated echo at the output of the adaptive filter. Whenever the double talk is detected, the adaptive algorithm is frozen. The proposed detector has a quick reaction to the onset and cessation of the double talk and we illustrate this with a few simulations with pre-recorded speech segments. Performance of the subband adaptive filter (Navaneetha Krishnan et al., Proceedings of the Eighth IEEE DSP Workshop, Utah, August, 1998) with the proposed double-talk detector is compared with that of Doherty and Porayath (IEEE Trans. Circuits Systems-II (May 1997) 389-396). We used ERLE and coefficient error vector norm as the performance measures.