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US 8,571,230 B2Granted
Active noise reduction adaptive filter adaptation rate adjusting
AssigneeBose Corporation
InventorsDavis Y. Pan, Christopher J. Cheng
Life of this patent
Estimating the term…
Abstract
A method for determining leakage factors or adaptation rates, or both, for adaptive filters in an active noise reduction system. The leakage factor or adaptation rate, or both, may vary depending on a parameter of an input reference signal. The parameter may include one or more of reference signal input frequency, rate of change of reference input signal frequency, if a predetermined triggering condition exits, or if a predetermined event has occurred.
Claims8
A vehicle noise reduction system comprising;
- circuitry for detecting engine speed and a rate of change of the engine speed of a vehicle engine;
- circuitry for determining an adaptation rate for use in an adaptive filter of the vehicle noise reduction system as a function of the rate of change of frequency of a reference input signal indicative of the engine speed, so that the adaptive filter adapts more rapidly when the engine speed is increasing or decreasing than when the engine speed is constant;
- circuitry for applying the adaptation rate to coefficients of the adaptive filter;
- and
- circuitry for applying the coefficient to an audio signal.
2 more elements
Dependencies are inferred from the claim text.