Patent ID: 7277538

Claim:
An audio communication device, comprising: a first audio signal input for receiving a first audio signal; a second audio signal input for receiving a second audio signal, wherein at least a portion of the second audio signal is an echo of the first audio signal; an echo cancellation device, including a subtractor having two inputs and one output, and configured to subtract signals presented on the two inputs to remove the echo and to output a subtracted signal on the subtractor output, the first subtractor input being connected to the first audio signal output, a noise reducer having an input connected to the subtractor output, and having an output, an auto gain control having an input connected to the noise reducer output, an audio sensing filter having an output connected to the subtractor second input, and having an input, the audio sensing module configured to compensate for distortions caused by sensing the first audio signal, an acoustic echo estimation filter having an output connected to the audio sensing module input, and having an output, said acoustic echo estimator configured to compensate for substantially linear changes in echo characteristics, and an audio generation filter having an output connected to the acoustic echo estimator input, and having an input connected to the second audio signal input, the audio generator configured to remove substantially nonlinear distortions associated with the formation of the first audio signal.