Abstract: A multichannel full-duplex audio signal transmission system, comprising an adaptive filter (2) provided for multichannel acoustic echo cancellation. A channel combining device (5) is provided between the preprocessing units (V1, . . . VD) and loudspeakers (L1, . . . ,LD), in which several (C>D) loudspeakers can be connected to one and the same preprocessing unit and by means of which the remaining D-C preprocessing units can be separated from the loudspeakers (L1, . . , LD). The channel combining device permits an optimization of the convergence ratio of the adaptive adjustment of filter coefficients in said adaptive filter (2).

Abstract: The present invention relates to a device and method for carrying out acoustic echo cancellation (2) when playing back C-channel audio signals on a D-channel audio signal transmission system with C<D. This invention can be used, for example, in videoconferencing, in which a variable number of active speakers are spatially played back according to the seating positions thereof. The aim of the invention is to solve for the poor convergence of the adaptive echo cancellation when the loudspeaker signals are strongly correlated. The invention provides that in addition to the known method of subjecting audio signals to preprocessing (V1, . . . , VD), which preferably induces a decorrelation, C output signals of the preprocessing units are selected by a channel combining device (5) and distributed to the loudspeakers (L1, . . . , LD), several signals being played back on a number of loudspeakers.