An audio
processing device for use in a network connected audio conferencing
system is provided, comprising: a network
microphone array comprising two or more microphones (mics) and a
beamforming circuit, wherein the network mic array is adapted to acquire acoustic audio signals, convert the same to electric audio signals, perform audio
beamforming on the electric audio signals, and output a digital combined
beamforming circuit output
signal that comprises a first
signal part and a second
signal part, and wherein the first signal part comprises a first set of digital bits that comprises an active beam index, and wherein the active beam index encodes a selected beam position out of a possible N beam positions, and wherein the second signal part comprises a second set of digital bits that comprises a beamformed
audio signal; a
receiver adapted to receive the digital combined beamforming circuit output signal and split the same into the first signal part and the second signal part; a plurality of acoustic echo cancellation filter devices, each of which are adapted to receive the second signal part and a far end reference
audio signal from a far end audio
processing device, and perform acoustic echo cancellation on the beamformed
audio signal in view of the far end audio signal; and an AEC filter circuit controller adapted to receive the first signal part,
decipher the active beam index encoded in the first beamformed audio signal part to determine which of the N beam positions is active, and select a corresponding one of the plurality of acoustic echo cancellation filter devices based on the active one of N beam positions to generate an output audio signal from the audio
processing device to be transmitted to the far end audio processing device.