Applying an auxiliary filter in the adaptive echo canceller for performance improvement of double-talk detection

This paper deals with the problem of double-talk (DT) detection in an acoustic echo canceller (AEC). In the DT detection algorithm with correlation coefficient, detection errors occasionally occur because it is hard to set the threshold to distinguish DT from echo path change (EPC). When EPC is erroneously considered as DT at the starting point of EPC, the adaptive filter can fall into the situation that it stops updating its filter coefficients. In addition, in case of echo path changing during the DT period, the end-point detection of DT period fails so that the adaptive filter cannot update its tap coefficients even after the DT period ends. To solve this problem, in this paper, we propose a new DT detection algorithm with an auxiliary filter. We use the idea that the error signal cannot be estimated using a reference signal in case of DT situation but it can be in case of EPC. The computer simulation verifies that the proposed method could solve the problem caused by the DT detection error or echo path change during the DT period.