Active attenuation system with specified output acoustic wave
First Claim
1. In an acoustic system having an input for receiving an input acoustic wave and an output for radiating an output acoustic wave, active attenuation apparatus for attenuating the output acoustic wave by introducing a canceling acoustic wave from an output transducer, comprising:
- an input transducer sensing the input acoustic wave;
an error transducer sensing the output acoustic wave and providing an error signal;
an adaptive filter model adaptively modeling said acoustic system and having a model input from said input transducer and an error input from the error signal and outputting a correction signal to said output transducer to introduce the canceling acoustic wave;
specifying means specifying the error signal to correspondingly specify the output acoustic wave such that a desired component already present in said input acoustic wave remains present in said output acoustic wave and is uncanceled by said canceling acoustic wave, wherein said specifying means comprises a summer summing the error signal with a desired signal and providing the resultant sum to said error input of said model such that said model outputs the correction signal to said output transducer to introduce the canceling acoustic wave and such that said desired signal is present in said output acoustic wave, and comprising a signal generator generating said desired signal, and wherein said summer sums the error signal and said desired signal from said signal generator and supplies the result to said error input of said model.
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Accused Products
Abstract
An active acoustic attenuation system specifies the error signal (44) to correspondingly specify the output acoustic wave. In the preferred embodiment, the error signal (44) is specified by summing (210) the error signal (44) with a desired signal (204) to provide a specified error signal (206) to the error input (202) of the adaptive filter model (40) such that the model (40) outputs the correction signal (46) to the output transducer (14) to introduce the canceling acoustic wave which specifies the output acoustic wave such that a desired signal is present in the output acoustic wave.
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Citations
8 Claims
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1. In an acoustic system having an input for receiving an input acoustic wave and an output for radiating an output acoustic wave, active attenuation apparatus for attenuating the output acoustic wave by introducing a canceling acoustic wave from an output transducer, comprising:
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an input transducer sensing the input acoustic wave; an error transducer sensing the output acoustic wave and providing an error signal; an adaptive filter model adaptively modeling said acoustic system and having a model input from said input transducer and an error input from the error signal and outputting a correction signal to said output transducer to introduce the canceling acoustic wave; specifying means specifying the error signal to correspondingly specify the output acoustic wave such that a desired component already present in said input acoustic wave remains present in said output acoustic wave and is uncanceled by said canceling acoustic wave, wherein said specifying means comprises a summer summing the error signal with a desired signal and providing the resultant sum to said error input of said model such that said model outputs the correction signal to said output transducer to introduce the canceling acoustic wave and such that said desired signal is present in said output acoustic wave, and comprising a signal generator generating said desired signal, and wherein said summer sums the error signal and said desired signal from said signal generator and supplies the result to said error input of said model. - View Dependent Claims (2, 3)
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- 4. An active acoustic attenuation system for attenuating an input acoustic wave comprising an output transducer introducing a canceling acoustic wave to attenuate said input acoustic wave and yield an attenuated output acoustic wave, an error transducer sensing said output acoustic wave and providing an error signal, an adaptive filter model modeling said acoustic system and having an error input from the error signal and outputting a correction signal to said output transducer to introduce the canceling acoustic wave, a summer summing the error signal with a desired signal and providing the resultant sum to said error input of said model such that said model outputs the corrections signal to said output transducer to introduce the canceling acoustic wave and such that said desired signal is present in said output acoustic wave, and comprising a signal generator generating said desired signal, and wherein said summer sums the error signal and said desired signal from said signal generator and supplies the result to said error input of said model.
Specification