A method for posterior frequency-domain multi-channel residual echo canceling

We propose a posterior frequency-domain multi-channel residual echo canceling method. As the number of reproduction channels of an echo canceller increases, its adaptive filter shows a slower convergence of the filter coefficient error, that is, large echo path mismatch. In this situation, the change in the human talker in a remote site produces an abrupt residual echo more frequently. The proposed method immediately cancels this abrupt residual echo by estimating it from loudspeaker-reproduced signals, adaptive filter output, and echo replica with a much shorter frame length compared with adaptive filter length. By taking the echo replica into account, this frequency-domain method can improve residual-echo estimates. Another feature of the proposed method is controlling the residual echo estimates according to the confidence interval of these estimates.