ACTIVE SOUND REDUCTION DEVICE AND ACTIVE SOUND INSULATION WALL MAKING USE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide an active sound reduction device capable of obtaining the better sound reduction effect by the smaller number of active sound reduction cells. SOLUTION: Active sound reduction cells A1 and A2 controlling so as to positively reduce a diffraction sound pressure component of a arrival noise are respectively arranged to a sound sourceside of the noise and a counter-sound source side as an opposite side of the sound sourceside, at the same time, the side of an edge section on the sound source side of the active sound reduction cell A1 on the sound source side and the side of an edge section on the counter- sound source of the active sound reduction cell A2 on the counter-sound source side become including toward the vertical center line of the active sound reduction device C, and a cross sectional shape of the active sound reduction device C is formed in an approximately inverted triangular shape as a whole.