Sound absorber
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiroyuki Takewa, Yutaka Torii
Life of this patent
Estimating the term…
Abstract
A sound absorber arrangement includes a plurality of sound absorbing layers of porous materials such as glass wool, rock fiber or cellular plastic, and high-polymer films, are alternately laminated in a direction perpendicular to a sound incidence plane. The layer thicknesses are increased in order in a direction away from the sound incidence plane. The sound absorber arrangement makes it possible to make a sound absorbing coefficient constant over the low to high frequency sound range.
Claims6
A sound absorber apparatus having a sound incidence surface extending generally along an incidence plane, said sound absorber apparatus comprising:
- a rectangular parallelepiped-shaped cabinet having a front surface baffle;
- a porous material sound absorption system fixed on said front surface baffle in parallel to the incidence plane;
- a plurality of perforated holes provided in said porous material sound absorption system and passing from said sound incidence surface through said front surface baffle of said rectangular parallelepiped-shaped cabinet;
- and
- cylindrical pipes respectively disposed in said holes, said cylindrical pipe having outer diameters substantially equal to diameters of said perforated holes, respectively, and having lengths different from lengths of said perforated holes, respectively.
Dependencies are inferred from the claim text.