Cirrus Logic Inc.

K Joshua Bodon

Jon David Hendrix

Shahram Tadayon

Brian Thornock

Aaron Treptow

Ziyan Zou

Sandeep Prasad Sira

An integrated circuit may include 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. The processing circuit may implement a feedback path comprising a feedback filter having a response that generates a feedback anti-noise signal based on the error microphone signal, the feedback filter comprising a plurality of biquad filters and wherein the anti-noise signal is generated from the feedback anti-noise signal and an 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 filter coefficients of one or more of the plurality of biquad filters to reduce the undesirable component.

Systems and methods for modifying biquad filters of a feedback filter in feedback active noise cancellation

A method may include receiving a user trigger signal indicating a user desire to update characteristics of an adaptive filter, receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer, wherein the transducer reproduces both a source audio signal 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, implementing the adaptive filter having a response that generates the anti-noise signal to reduce the presence of the ambient audio sounds in the error microphone signal, determining an acoustic coupling of the transducer to an error microphone for producing the error microphone signal, and responsive to a change in the acoustic coupling, prompting a user to assert the user trigger signal to indicate user desire to update characteristics of the adaptive filter.

On-demand adaptive active noise cancellation system

On-demand adaptive active noise cancellation

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Austin, TX, United States of America

K Joshua Bodon