Patent ID: 9486823
Filing Date: 2016-11-08
CPC Classification: B05B,G10K,H04R

Claim Text:
1. A method for acoustic noise cancellation (ANC) in a personal listening device, comprising: performing an acoustic noise cancellation (ANC) process during in-the-field use of the personal listening device using an adaptive control filter to produce anti-noise by the personal listening device, the ANC process computing an adaptive path filter in accordance with an adaptive filter control algorithm, the adaptive path filter estimating a transfer function of a signal path between an earpiece speaker of the personal listening device and an error microphone that are configured to be located at a user's ear; making a first copy of the adaptive path filter; detecting an off-ear condition using an adaptive path filter-based detection metric determined from information that is in the first copy of the adaptive path filter; and one of a) slowing down or freezing adaptation of the adaptive control filter, or b) disabling the ANC process so as to power down the ANC process, in response to the off-ear condition being detected.