SOUND-PROOF DEVICE

Japanese Patent JP3275472

B2

PURPOSE: To largely reduce a noise in a sound-proof room.
CONSTITUTION: A sound-proof room 11 is equipped with an entrance side sound absorbing duct 12, exit side sound absorbing duct 13, and inspection room 14. Also, the sound-proof room 11 is equipped with first pressure detectors 18 and 19 and second pressure detectors 23 and 24 which detect a pressure outside the sound-proof room 11, third pressure detectors 26 and 27 which detect the pressure inside the sound-proof room, arithmetic unit 28 which calculates an acoustic wave signal for suppressing a pressure near the third pressure detectors 26 and 27 by opposite phase intereference by an acoustic wave based on the signals of the first pressure detectors 18 and 19, the second pressure detectors 23 and 24, and the third pressure detectors 26 and 27, and acoustic wave generating means 29 and 30 which generate an acoustic wave. Thus, the noise can be sharply reduced by the phase interference by the acoustic wave, and a synthetic silencing effect can be improved by increasing the silencing effect of a high frequency component by the sound absorbing ducts 12 and 13.

Yasuhiro Umekage
Masamitsu Kondo

JP21164293A

April 15, 2002

August 26, 1993

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Matsushita Electric Industrial Co., Ltd

E04B1/82; B23Q7/00; B23Q41/02; G10K11/178; H03H21/00; H04B3/04; (IPC1-7): G10K11/178; B23Q7/00; B23Q41/02

JP342999A
JP5143086A
JP420994A
JP3272299A
JP4240894A
JP527774A
JP285637A
JP3274897A
JP4308898A
JP427296A
JP3195296A
JP6478600A
JP418900U

Fumio Iwahashi (2 others)

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