| 摘要 |
PURPOSE:To efficiently realize only a specific area as a silent space area of less noise by controlling at least one of the phase and the amplitude of the acoustic wave radiated from an additional sound source arranged in the vicinity of a noise source. CONSTITUTION:When the noise level will be reduced in a space area U' where the noise level should be reduced, an additional sound source S which has a 1/9 acoustic wave surface of a noise source N as a panel sound source is arranged under and in the vicinity of the noise source N, and both of the phase and the amplitude of its acoustic wave So are properly controlled by a controller 5 to obtain isacoustic level lines, and therefore, the most silent space is realized in the space area U' where the noise level should be reduced, and a space is obtained where the noise is lower according as going to the area U'. Thus, it is discriminated that the silent area where the noise level is effectively reduced is realized across the wide area including the area U' where the noise level should be reduced, and silencing of the directional three- dimensional space is possible. |
