US Patent 9928847 System and method for acoustic echo cancellation

An audio or video conferencing system having an array comprised of two or more microphones and having one or more loudspeakers positioned proximate to the microphones. The conferencing system also has acoustic echo cancellation (AEC) functionality that removes direct and reverberant acoustic echo from microphone signals in two separate acoustic echo cancellation operations. The first AEC operation removes direct acoustic echo prior to a beamforming operation, and the second AEC operation removes reverberant acoustic echo from a microphone signal subsequent to the beamforming operation.