Narrowband cancellation
AssigneeBose Corporation
InventorsYashar Motedayen Aval, Siamak Farahbakhsh
Life of this patent
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Abstract
Noise cancellation systems and methods are provided that generate an anti-noise signal configured to destructively interfere with noise in a cancellation zone. The systems and methods receive a signal representative of the noise in the cancellation zone. The signal is analyzed to identify a frequency to be reduced in the cancellation zone, and the signal is down converted to place the identified frequency at baseband. A baseband anti-noise signal is generated based upon the down converted signal. The baseband anti-noise signal is up converted to the identified frequency to produce an anti-noise signal having components at the identified frequency, and the anti-noise signal is provided to be transduced into an acoustic signal.
Claims20
A method of reducing noise comprising:
- receiving a signal representative of noise in a cancellation zone;
- identifying a frequency within the signal to be reduced in the cancellation zone;
- down converting the signal to place the identified frequency at baseband;
- generating a baseband anti-noise signal based upon the down converted signal;
- up converting the baseband anti-noise signal to the identified frequency to produce an anti-noise signal having components at the identified frequency;
- and
- providing the anti-noise signal to be transduced into an acoustic signal.
A noise cancellation system comprising:
- a sensor configured to provide a signal representative of noise in a cancellation zone;
- and
- a controller coupled to the sensor and configured to:
- receive the signal from the sensor,
- identify a frequency within the signal to be reduced in the cancellation zone,
- down convert the signal to place the identified frequency at baseband,
- generate a baseband anti-noise signal based upon the down converted signal,
- up convert the baseband anti-noise signal to the identified frequency to produce an anti-noise signal having components at the identified frequency, and
- provide the anti-noise signal to be transduced into an acoustic signal.
Dependencies are inferred from the claim text.