Noise cancellation system

Abstract

A method of adaptive noise cancellation can include receiving an audio input signal, receiving an ambient signal through a microphone, modifying filter parameters of a noise filter based on the ambient signal, and filtering the audio input signal based on the modified filter parameters.

What is claimed is: 
     
         1 . A method of adaptive noise cancellation, the method comprising:
 receiving an audio input signal;   receiving an ambient signal through a microphone   modifying filter parameters of a noise filter based on the ambient signal; and   filtering the audio input signal based on the modified filter parameters.   
     
     
         2 . The method of adaptive noise cancellation according to  claim 1 , the method further comprising filtering the ambient signal based on the modified filter parameters. 
     
     
         3 . The method of adaptive noise cancellation according to  claim 1 , in which the noise cancellation occurs in a noise processor, the method further comprising modifying operating instructions of the processor based on the ambient signal. 
     
     
         4 . An adaptive gain system, comprising:
 a speaker;   a feedback microphone configured to sample the speaker;   a feed-forward microphone configured to sample a listening environment;   a controllable amplifier electrically coupled between the feed-forward microphone and the speaker; and   an adaptivity controller electrically coupled with the controllable amplifier and configured to control the controllable amplifier based at least in part on output from the feedback microphone and output from the feed-forward microphone.   
     
     
         5 . The adaptive gain system according to  claim 4 , further comprising a correlator electrically coupled with the adaptivity controller and configured to cause the adaptivity controller to adjust a gain of the controllable amplifier. 
     
     
         6 . The adaptive gain system according to  claim 4 , further comprising a feed-forward filter electrically coupled between the feed-forward microphone and the controllable amplifier. 
     
     
         7 . An adaptive noise canceling system, comprising:
 a noise cancellation processor, including:
 an audio input for receiving an input audio signal, 
 a microphone input structured to receive one or more microphone signals from a monitored environment, and 
 a filter processor structured to produce a filtering function based on one or more filter parameters; and 
   an adaptivity processor structured to change the one or more filter parameters in the noise cancellation processor based on a changing operating environment of the adaptive noise canceling system.   
     
     
         8 . The adaptive noise canceling system of  claim 7 , in which the noise cancellation processor further comprises a parameter store structured to store a plurality of filter parameters, and in which the adaptivity processor is structured to select one or more filter parameters from the parameter store based on the changing operating environment. 
     
     
         9 . The adaptive noise canceling system of  claim 7 , in which the noise cancellation processor further comprises a set of operating instructions and which the adaptivity processor is structured to modify the set of operating instructions based on the changing operating environment.