Abstract: An acoustical system for damping and absorption of sound in rooms to provide a sound damping even at very low frequencies, e.g. 50 Hz, and simultaneously improve speech comprehension in the entire room by reduction of the resonance time. The acoustic absorption can be varied to vary the resonance time over the entire part of the frequency area. The sound absorbents 14 in the form of plates, mats or similar constructions, are arranged at an angle in at least one corner area 11 formed by the walls 12 and ceiling 13 of the room. In the corner area 11 behind the absorbent 14, an air volume is trapped so that the absorbent due to the sound influence has a membrane effect. The inclination and position of each absorbent 14 can be varied individually or in groups.