Combined echo and noise reduction for distributed microphones

This work presents an echo and noise suppression approach that can be used in teleconference systems. The problem in such hands-free telecommunication scenarios is the possible large distance between the local speakers and the microphones. The microphones are placed more than 40cm apart from each other to accomplish a better compromise for different speaker positions. A microphone diversity approach is presented which exploits these different signal and noise conditions at the microphones. In general teleconference systems require additional signal processing for echo cancellation. To reduce possible background noise from the microphone input signals the system contains a Multichannel Wiener Filter. The main contribution of this paper is an extension of the Multichannel Wiener Filter for combined noise reduction and residual echo suppression.