US 12,302,057 B1
Adaptive virtual microphone for earbuds
Hanchi Chen, Cupertino, CA (US); Martin Kuster, Los Gatos, CA (US); Tom-Davy W. Saux, Los Gatos, CA (US); and Victoria Chiu, Emerald Hills, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Jun. 30, 2022, as Appl. No. 17/855,132.
Claims priority of provisional application 63/237,792, filed on Aug. 27, 2021.
Int. Cl. H04R 1/10 (2006.01); G10K 11/178 (2006.01)
CPC H04R 1/1083 (2013.01) [G10K 11/17825 (2018.01); G10K 11/17833 (2018.01); G10K 11/17854 (2018.01); H04R 1/1016 (2013.01); H04R 2460/01 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for performing adaptive noise cancellation (ANC) for an earphone, the method comprising:
generating, using an adaptive filter of the ANC, an anti-noise signal from ambient noise captured by a reference microphone of the earphone to attenuate leakage noise from the ambient noise, wherein the adaptive filter is being updated by an adaptive filter controller;
determining an estimated level of the leakage noise based on the adaptive filter;
determining a bias term for the adaptive filter based on the estimated level of the leakage noise;
applying the bias term to the adaptive filter to change the anti-noise signal to attenuate the leakage noise received at an ear drum of a user wearing the earphone; and
reducing an error term that is being input to the adaptive filter controller, the error term comprises an error noise signal captured by an error microphone, wherein the error term is reduced by subtracting an estimated change to the error noise signal that is due to the bias term being applied to the adaptive filter.