2022-03-082022-03-081999https://publica.fraunhofer.de/handle/publica/304442DE 29815712 U UPAB: 20000725 NOVELTY - The absorbers are less than 0.3 m deep and have a closed, flat, acoustically transparent surface, and have several layers (2-4). The inner panels (3) are made of metal or heavy sheeting of variable thickness for absorption in different frequency ranges. The panels of the soundproofing are completely enclosed by the absorber. A hollow cavity (7) is arranged behind the sound proofing. The back wall is in the form of a metal or sheet plate (6). USE - Sound proofing panel for entire hearing range, especially below 100 Hz. ADVANTAGE - The sound proofing panels for walls, ceilings and floors enable installation ducts and lights to be incorporated.de608624690utility model1997-19738757