A virtual stereo approach to stereophonic acoustic echo cancellation

Abstract

This paper proposes a virtual stereo approach that behaves like a stereo system but requires a standard mono-aural communication channel. Since it is known that in teleconferencing systems most of the conversations take place with one active talker at a time, the stereo perception can be easily realized by delaying and scaling a single signal. At the far-end side the system obtains a single-channel signal by performing a direction-of-arrival (DOA) estimation and a passive beamforming on the true stereo signal, while at the near-end side it uses an active beamformer to reproduce the stereo effect. A single acoustic echo canceler can now be used, with some advantages over the true stereophonic system. The proposed architecture can be easily integrated into the recent videoconferencing systems with the capability of automatically locating the active talker, since they already perform DOA estimation and beamforming. The information on the DOA is included into the coded digital stream or can be perceptually hidden into the speech signal over standard analog channels.