Patent ID: 9361872
Filing Date: 2016-06-07
CPC Classification: G10K

Claim Text:
1. A method of producing an antinoise signal, said method comprising: producing the antinoise signal during a first time interval by applying a digital filter to a reference noise signal according to a first state of the digital filter that includes a filter gain; calculating a second state of the digital filter that is different than the first state of the digital filter and includes an update for said filter gain; and producing the antinoise signal during a second time interval subsequent to the first time interval by applying the digital filter to the reference noise signal according to said second state of the digital filter, wherein said applying the digital filter to the reference noise signal includes: applying a filter to the reference noise signal, in a filtering domain having a first sampling rate, to produce a filtered signal; and controlling a gain of the filtered signal according to the filter gain to produce the antinoise signal, and wherein said calculating the second state of the digital filter includes: applying a copy of said filter to the reference noise signal, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, to produce a second filtered signal; and calculating said update based on information from said second filtered signal and on information from an error signal.