Noise reduction device
AssigneePanasonic Corporation
InventorsKeiji Mori, Hiroyuki Kano, Tsuyoshi Maeda, Yoshifumi Asao
Life of this patent
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Abstract
A noise control device includes the following structural elements. A signal memory records both of a noise signal supplied from a noise microphone and an error signal supplied from an error microphone. A filter coefficient calculator calculates a fixed filter coefficient of a control filter by using data recorded in the signal memory. A filter coefficient renewing section renews, at a given timing, a filter coefficient set at a fixed filter in a control filter to a filter coefficient read out from the filter coefficient calculator.
Claims5
A noise control device for reducing a given noise arriving at a control point by radiating a control sound toward the control point, the noise control device comprising:
- a controlling noise detector for detecting a given coming-noise and outputting a controlling noise signal;
- a control filter for processing the controlling noise signal supplied from the controlling noise detector by using a fixed filter coefficient set in advance, and thereby outputting a control signal;
- a control speaker radiating a control sound based on the control signal supplied from the control filter for reducing the given noise arriving at the control point;
- an error detector placed at the control point for detecting an error signal between the noise and the control sound that is supplied from the control speaker;
- a signal memory for storing the controlling noise signal supplied from the controlling noise detector and an error signal detected by the error detector;
- a filter coefficient calculator for calculating a filter coefficient by using the controlling noise signal and the error signal both stored in the signal memory;
- and
- a filter coefficient renewing section for renewing, at a given timing, a fixed filter coefficient set at the control filter to a filter coefficient calculated by the filter coefficient calculator.
Dependencies are inferred from the claim text.