Patent ID: 8204249

Claim:
A method for reducing acoustic echoes in a plurality of microphone-digital signals transmitted from a first location to a second location, the method comprising: providing a plurality of loudspeakers and a plurality of microphones located at the first location, each of the plurality of microphones produces one of the plurality of microphone-digital signals that includes sounds produced at the first location and acoustic echoes produced by the plurality of loudspeakers; determining approximate impulse responses, each approximate impulse response corresponds to an echo path between each of the plurality of microphones and each of the plurality of loudspeakers; determining a plurality of approximate acoustic echoes, each approximate acoustic echo corresponds to convolving a digital signal played by one of the plurality of loudspeakers with a number of the approximate impulse responses; and reducing the acoustic echo in at least one of the microphone-digital signals based on the corresponding approximate acoustic echo; wherein determining an approximate impulse response further comprises identifying a type of audio transmission associated with each echo path as one of the following: audio signals produced at the first location only; audio signals produced at the second location only; audio signals simultaneously produced at the first location and the second location; and no audio signals produced at either the first location or the second location.