A coustic echo canceller with multiple echo paths

A new configuration of acoustic echo canceller for multiple microphone teleconferencing systems is proposed. It is designed for use with microphones whose gains switch or vary during teleconferencing according to the talker. This system requires memory for multiple echo paths, which enables the updating of filter coefficients when an echo path is changed due to the switching of the actuated microphone during talker alternation. In comparison to the single echo path model which uses only adaptation, this method maintains echo cancellation during abrupt changes of the echo path when the microphone alternates between talkers. Also in comparison to direct microphone output mixing, this method reduces the stationary residual echo level by the reduction of acoustic coupling.