HYBRID ADAPTIVE NOISE CANCELLATION SYSTEM WITH FILTERED ERROR MICROPHONE SIGNAL

摘要

In accordance with systems and methods of the present disclosure, an adaptive noise cancellation system may include an alignment filter configured to correct misalignment of a reference microphone signal and an error microphone signal by generating a misalignment correction signal.

主权项

1. An integrated circuit for implementing at least a portion of a personal audio device, comprising:
an output for providing a signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering an effect of ambient audio sounds in an acoustic output of the transducer; a reference microphone input for receiving a reference microphone signal indicative of the ambient audio sounds; 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 feedforward filter having a response that generates at least a portion of the anti-noise signal from the reference microphone signal;a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal;a feedback filter having a response that generates at least a portion of the anti-noise signal based on the error microphone signal;an alignment filter configured to correct misalignment of the reference microphone signal and error microphone signal by generating a misalignment correction signal;a feedforward coefficient control block that shapes the response of the feedforward filter by adapting the response of the feedforward filter to minimize the ambient audio sounds in the error microphone signal; anda secondary path coefficient control block that shapes the response of the secondary path estimate filter in conformity with the source audio signal and the misalignment correction signal in order to minimize the misalignment correction signal.