Patent ID: 6167985
Filing Date: 2001-01-02
Classification: G10K

Abstract:
A .lambda./4-absorber for the absorption of sound, such as is generated by machines, in particular by vehicles, comprising: a plurality of tubular .lambda./4-resonators wherein each .lambda./4-resonator has an opening region having a plurality of spaced apart openings which border on a sound reflecting surface; a plurality of interaction zones corresponding to each of said plurality of spaced apart openings, wherein an impinging sound wave destructively interferes with a standing sound wave formed in said .lambda./4-resonator, and wherein said plurality of interaction zones are distributed to cover a sound reflecting surface and each of said plurality of interaction zones does not significantly overlap another of said plurality of interaction zones; wherein a band width of a resonant frequency response of said .lambda./4-resonators can be adjusted by a first means for changing a sound energy loss in said opening region, said first means having a low air flow resistance approximately equivalent to that of a wide-meshed grid.