SYSTEMS AND METHODS FOR PERFORMANCE AND STABILITY CONTROL FOR FEEDBACK ADAPTIVE NOISE CANCELLATION

摘要

A method for cancelling ambient audio sounds in the proximity of a transducer may include receiving an error microphone signal indicative of the output of the transducer and ambient audio sounds at the transducer. The method may also include generating an anti-noise signal for countering the effects of ambient audio sounds at an acoustic output of the transducer, wherein generating the anti-noise signal comprises applying a feedback filter having a response that generates a feedback anti-noise signal based on the error microphone signal and applying a variable gain element in series with the feedback filter. The method may further include monitoring whether an ambient audio event is occurring that could cause the feedback filter to generate an undesirable component in the anti-noise signal and controlling the gain of the variable gain element to reduce the undesirable component.

主权项

1. An integrated circuit for implementing at least a portion of a personal audio device, comprising:
an output for providing an output signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer; an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements:
a feedback path comprising:
a feedback filter having a response that generates a feedback anti-noise signal based on the error microphone signal; anda variable gain element in series with the feedback filter; andan event detection and oversight control that detects that an ambient audio event is occurring that could cause the feedback filter to generate an undesirable component in the anti-noise signal and controls the gain of the variable gain element to reduce the undesirable component.