A Perspective on Stereophonic Acoustic Echo CancellationSingle channel hands free teleconferencing systems are becoming popular. In order to enhance the communication quality of these systems, more and more stereophonic sound devices with two loudspeakers and two microphones are deployed. Because of the coupling between loudspeakers and microphones, there may be strong echoes, which make real time communication very difficult. The best way we know to cancel these echoes is via a stereo acoustic echo