An active noise control device detects composite vibration of a vibration transmitting route to which both vibration of a rotating body caused by generation or transmission of drive force of a vehicle and vibration of a wheel generated by contact between the wheel and a road surface are transmitted. A first reference signal for defining a reference waveform of a canceling sound for canceling vibration noise in a vehicle interior is generated based on the composite vibration. The component of the canceling sound for canceling vibration noise of the rotating body is removed from the first reference signal to generate a second reference signal for defining a reference waveform of the canceling sound for canceling vibration noise of the wheel. The canceling sound is outputted based on the second reference signal.

Active noise control device

A audio output device includes: a speaker position detecting unit which detects the position of a speaker; a masking sound producing section which produces a masking sound; a plurality of loudspeakers which output the masking sound; and a localization controlling section which controls a localization position of the masking sound based on the speaker position detected by the speaker position detecting unit, and which supplies a sound signal relating to the masking sound to at least one of the plurality of loudspeakers.

Audio output device and audio output method

PROBLEM TO BE SOLVED: To provide an active noise control device and an active noise control method, for maintaining a spatial area which gives a silence effect with its size reduced. SOLUTION: The active noise control device includes: a reference microphone 11 for detecting noise; a control speaker 13 for outputting a control sound; a near field characteristic detecting microphone 12 arranged in parallel with the control speaker 13; a circuit K1 for identifying a first transfer characteristic T n ; a circuit K2 which calculates a characteristic C m from the control speaker 13 to a near characteristic detection microphone 12, according to the first transfer characteristic T n , a second transfer characteristic T f and a second error characteristic C f , and which constitutes a control filter W for reducing noise in a control area by performing phase interference between the control sound and the noise, according to the first transfer characteristic Tn and the characteristic C m ; and a circuit K3 for controlling a control sound of the control speaker 13, on the basis of a detection result of the reference microphone 11 and the control filter W. COPYRIGHT: (C)2011,JPO&INPIT

Device and method for controlling active noise

PROBLEM TO BE SOLVED: To provide a noise reducing apparatus which can reduce noise diffused from a noise source in a wide range even if noise has directivity. SOLUTION: When noise from the noise source has directivity, the directivity of the noise from the noise source is calculated based on sound wave information items of a sensor microphone and a speaker proximity microphone 38 by a signal processing section, and a directivity correction coefficient is calculated for each speaker 12 according to the calculated directivity. Then the directivity correction coefficient is set for each delay circuit, and the amplitude of a reducing signal is corrected in a manner of correcting the intensity of a control sound according to the directivity correction coefficient. Thus the directivity of a control sound emitted from each speaker 12 becomes equal to the directivity of the noise, and therefore even if the noise from the noise source has the directivity, the noise from the noise source can be canceled in a wide range inclusive of a control point. COPYRIGHT: (C)2008,JPO&INPIT

Nakajima Tatsumi

Papers

Noise reducing apparatus