Patent ID: 8385559

Claim:
An adaptive noise cancellation system for a headset, the noise cancellation system comprising: a plurality of reference microphones configured to detect a noise signal; an error microphone configured to detect an acoustic error signal; a controller connected to the plurality of reference microphones and the error microphone, the controller configured to control adaptation of an infinite impulse response (“IIR”) canceller filter based at least in part on a stability determination for the noise cancellation system and a secondary path model, control updating of the secondary path model, generate an anti-noise signal based on the IIR canceller filter, and output the anti-noise signal; wherein the IIR canceller filter is generated by converting a finite impulse response (“FIR”) canceller filter using a balanced model reduction technique; wherein the anti-noise signal is electrically combined with an audio signal to generate a combined signal, and the combined signal is provided to a speaker; and wherein the secondary path model is updated when a communication signal approximates a white noise signal and the communication signal is larger than a threshold value.