Multi-microphone residual echo estimation

Post-filters are a powerful extension to improve echo attenuation when combined with the well-known echo canceller. In order to guarantee high quality of the transmitted speech signal, the primary purpose of a post-filtering system is to estimate the power spectral density (PSD) of the residual echo at the output of the echo canceller as accurately as possible. We introduce a novel technique to estimate the residual echo by using a microphone array. The robustness against double-talk and other additive interferences is reached by means of minimum statistics and further enhanced by exploiting spatial information. Simulation results show that the new methods are able to estimate the residual echo even under adverse conditions.