SOUND ABSORBING ELEMENT Russian patent published in 2014 - IPC E04B1/84 

FIELD: machine building.

SUBSTANCE: sound absorbing element comprises a smooth surface and a perforated surface between which a multilayer sound absorbing structure is placed and consists of three layers of a sound-absorbing material. The first layer is more rigid, solid and profiled and is fixed on the smooth surface. The second layer is softer than the first one, is intermittent and placed in the focus of the sound reflecting surfaces of the first layer. The third layer is made from a foamed sound absorbing material, for example, construction sealing foam insulation, and is placed between the first layer and the perforated surface of the sound absorbing element.

EFFECT: enhanced efficiency of sound absorption and reliability of the structure on the whole.

6 cl, 1 dwg