Patent ID: 8170226

Claim:
A machine-implemented method for performing acoustic echo cancellation, comprising: calculating, by an acoustic echo canceling module, an initial offset with respect to an audio render signal and an audio capture signal; dividing, by a filter bank, samples of the audio capture signal into sub-band samples of the audio capture signal for a plurality of sub-bands; dividing, by the filter bank, samples of the audio render signal into sub-band samples of the audio render signal for the plurality of sub-bands; setting a delay to an initial value; producing, by respective short length adaptive filters, a respective output signal representing echo cancelled signal[n, k, d], where n is a time frame index, k is a sub-band index, and d is a delay index, each of the respective short length adaptive filters corresponding to a different respective one of the plurality of sub-bands, the respective short length adaptive filters receiving, as input, an audio capture signal[n−d, k] for a corresponding sub-band and an audio render signal[n−d, k] for the corresponding sub-band; calculating echo return loss enhancement[d, k] for a delay corresponding to the delay index, d, for each of the plurality of sub-bands, based on the audio capture signal[n−d, k] and the echo cancelled signal[n, k, d]; selecting the echo return loss enhancement[d, k], from among all of the plurality of sub-bands, having a highest value to obtain echo return loss enhancement[d] for the delay; incrementing the delay index d; repeating the producing, the calculating, the selecting and the incrementing until the delay index d corresponds to a delay that is greater than a given maximum delay; and selecting a final test delay setting corresponding to a highest echo return loss enhancement from among all of the echo return loss enhancement[d] as an estimate of a speaker to microphone alignment offset with respect to the calculated initial offset, when the delay is greater than the given maximum delay.