Patent ID: 9076427
Filing Date: 2015-07-07
Classification: G10K

Abstract:
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 for providing at least one microphone signal indicative of the ambient audio sounds and that contains a component due to the acoustic output of the transducer; and a processing circuit that generates the anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener, wherein the processing circuit implements an adaptive filter having a response that shapes the source audio and a combiner that removes the source audio from the at least one microphone signal to provide a corrected microphone signal, wherein the processing circuit determines a relative magnitude of a source audio component of the acoustic output of the transducer present in the at least one microphone signal and the ambient audio sounds present in the at least one microphone signal, wherein the processing circuit determines a degree of coupling between the transducer and an ear of the listener and adjusts the determined relative magnitude of the source audio component of the acoustic output of the transducer present in the at least one microphone signal and the ambient audio sounds present in the at least one microphone signal in conformity with the determined degree of coupling, and wherein the processing circuit takes action to prevent improper adaptation of the adaptive filter in response to determining that the relative magnitude of the source audio component of the acoustic output of the transducer present in the at least one microphone signal to the ambient audio sounds present in the at least one microphone signal indicates that the adaptive filter may not adapt properly.