| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and a device for reducing ultra-low frequency sound transmission, which suppresses that ultra-low frequency sound leaks from an aperture of an ultra-low frequency sound-proof house which is always open. SOLUTION: In the method and the device for reducing ultra-low frequency sound transmission, which includes the ultra-low frequency sound-proof house 1 for covering an ultra-low frequency sound source 3, and a reactance type silencer 4 for ultra-low frequency, provided at the always opened aperture of the ultra-low frequency sound-proof house 1, and which reduces ultra-low frequency sound emitted from an aperture section 2 to outside, the reactance type silencer 4 for ultra-low frequency includes an entrance section 2 and an exit section 5 of predetermined perimeter lengths l<SB>1</SB>and l<SB>2</SB>, which are proportional to an apparent resistance component of acoustic impedance, and the apparent resistance component is increased by developing an acoustic boundary layer in proportion to the perimeter length l<SB>1</SB>and l<SB>2</SB>, and the ultra-low frequency is reduced by converting acoustic energy to thermal energy. COPYRIGHT: (C)2010,JPO&INPIT
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