Patent ID: 9711130
Date: 2017-07-18
CPC Classifications: G10K,H04R

Claim:
1. A personal audio device, comprising: a personal audio device housing; a transducer mounted on 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; at least one microphone mounted on the housing in proximity to the transducer for providing at least one microphone signal indicative of the acoustic output of the transducer and the ambient audio sounds at the transducer; a processing circuit that implements an adaptive filter having a response that generates the anti-noise 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 at least one microphone signal by adapting the response of the adaptive filter to minimize a component of the at least one microphone signal due to the ambient audio sounds, wherein the processing circuit further implements a first filter having a first frequency response that filters the at least one microphone signal to provide an input to the adaptive filter from which the anti-noise signal is generated, and wherein the processing circuit further implements a second filter having a second frequency response that differs from the first frequency response, wherein the second filter filters the at least one microphone signal to provide a first input to the coefficient control block.