×

Active noise reduction adaptive filter adaptation rate adjusting

  • US 8,306,240 B2
  • Filed: 10/20/2008
  • Issued: 11/06/2012
  • Est. Priority Date: 10/20/2008
  • Status: Active Grant
First Claim
Patent Images

1. A method, comprising:

  • in a vehicle noise reduction system, detecting the engine speed and the rate of change of the engine speed of a vehicle engine;

    determining an adaptation rate for use in an adaptive filter of the vehicle noise reduction system based on 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;

    applying the adaptation rate to coefficients of the adaptive filter;

    applying the coefficients to an audio signal; and

    transducing the audio signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×