Patent AT-E187570-T1: [Translated] SOUND ABSORPTION ARRANGEMENT WITH ACTIVE DOUBLE WALL

PCT No. PCT/FR94/00520 Sec. 371 Date Feb. 15, 1996 Sec. 102(e) Date Feb. 15, 1996 PCT Filed May 4, 1994 PCT Pub. No. WO94/27283 PCT Pub. Date Nov. 24, 1994An active double wall comprises two parallel plates defining a rectangular space. Four sensors are positioned between the plates so as to detect noises in said space, and four actuators are placed between the plates to emit counter-noises in the space. The actuators are phase-controlled by a control unit in order to minimize the sum of the outputs of the sensors. The actuators are respectively positioned at the centers of the sides of the rectangular space, and the sensors are respectively positioned at the centers of the sides of a rhombus whose vertices are the respective centers of the sides of the rectangular space, or vice-versa.