Hitachi, Ltd.

Ryouji Sato

Masahiro Ito

Takao Senshu

Hirokiyo Terada

Shinichi Shimode

Minetoshi Izushi

Masamichi Hanada

Hiroshi Takenaka

Shinya Okabe

An active noise control system for a three-dimensional space, including noise detecting means, sound generating means, noise control effect detecting means and a control device consisting of a phase of a wave signal fed from the noise detecting means wherein a plurality of noise control effect detecting means and sound generating means are disposed at a distance shorter than a wavelength of the noise to be controlled, and input signals of the respective sound generating means and output signals of the respective noise control effect detecting means are fed through filters, separately, to control the sound for active noise control. In case of an air conditioner, the noise control effect detecting means are disposed at positions where an air stream flowing through the air conditioner is not obstructed thereby.

Active noise control apparatus for three-dimensional space

Growing community of inventors

Shimizu, Japan

Ryouji Sato