Patent ID: 8411873
Filing Date: 2013-04-02
Classification: B64C,G10K

Abstract:
1. A noise control device for reducing, by emitting a control sound toward a control point, a given noise arriving at the control point, the noise control device comprising: a controlling noise detector for detecting the given noise to output a controlling noise signal; a controlling filter section, including a fixed filter having a filter coefficient fixed therein, for signal-processing the controlling noise signal outputted from the controlling noise detector, in a state where the filter coefficient is fixed in the fixed filter, to output a control signal; a control speaker for reducing the given noise arriving at the control point, by emitting toward the control point a control sound based on the control signal outputted from the controlling filter section; a noise determination section for determining whether or not the given noise arriving at the control point is a noise corresponding to the filter coefficient of the fixed filter; and an output control section for stopping output of the control signal from the controlling filter section when the noise determination section determines that the given noise is not a noise corresponding to the filter coefficient of the fixed filter, wherein the noise determination section includes: the output control section stops the output of the control signal from the controlling filter section, when the level determination section determines that the level of the output signal from the adder is higher than the predetermined threshold.