Patent ID: 9264808
Filing Date: 2016-02-16
CPC Classification: G10K,H04R

Claim Text:
1. A personal audio device comprising: a personal audio device housing; a transducer coupled to the housing for reproducing an audio signal including both source audio for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer; a reference microphone coupled to the housing for providing a reference microphone signal indicative of the ambient audio sounds; an error microphone coupled to the housing in proximity to the transducer for providing an error microphone signal indicative of the acoustic output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements an adaptive filter having a response that generates the anti-noise signal from the reference microphone signal to reduce the presence of the ambient audio sounds heard by the listener, wherein the processing circuit implements a coefficient control block that shapes the response of the adaptive filter in conformity with the error microphone signal and the reference microphone signal by adapting the response of the adaptive filter to minimize the ambient audio sounds in the error microphone signal and by further adapting the response of the adaptive filter in accordance with a calculated narrow-band-to-full-band ratio, wherein the narrow-band-to-full-band ratio is a function of a narrow-band power of the reference microphone signal divided by a full-band power of the reference microphone signal.