To contrive effective reduction of noise in a low frequency band by incorporating a resonance sound absorption system into hollow structure or solid structure.
A resonance sound absorption system 2 is constituted of a body part 21 for forming to utilize the beam 1 of hollow structure or solid structure whose inside is partially drilled and having a cavity part, a neck part 22 communicating with the body part 21, and an opening part 23 opened toward the inside of a room. The system 20 reduces and absorbs a standing wave generated in the room by utilizing a resonance phenomenon caused by the mass of air existing in the communicating passage of the neck part 22 and the air spring component of the cavity part of the body part 21. Thereby the noise level of a low frequency band which causes the highest concern in a weight source floor impact sound can be reduced, the resonance sound absorption system can be disposed without being projected into the room, and if part of the resonance sound absorption system is made variable structure, minute adjustment can be finely performed in accordance with a condition of the room.
TSUKADA SUSUMU
INABA KENJI
TAKESHITA MICHITAKA
