Stereophonic acoustic echo cancellation-an overview of the fundamental problem

As teleconferencing systems evolve to an ever more lifelike and transparent audio/video medium, it will be necessary to incorporate multichannel audio, which at a minimum involves two channels, i.e., stereophonic sound. However, before full-duplex stereophonic teleconferencing can be deployed, the acoustic echo cancellation (AEC) problem must be solved in this regime. This paper draws attention to a fundamental problem of multichannel AEC that concerns the nonunique nature of the estimated receiving room impulse responses. Various potential solutions are discussed but are shown to be not entirely satisfactory.<>