| 摘要 |
A device having a high sound absorption ability and intended for use as floor, wall and/or ceiling facing in so-called echo-free rooms (10), i.e. in acoustic measuring rooms designed according to international standard, ISO-3745, in picture and sound recording studios, in sound laboratories etc, in which a sound propagation as in a free field is desired. The new device is based on sound absorbents in the form of plates (16, 20) forming a substrate support (16) and units (20) projecting obliquely from this which are so placed that they have a wave-like cross-section. The size and reciprocal angular conditions of the sound absorbents (20) projecting from the substrate support (16) are chosen so that at least double reflection is always obtained before a sound wave deriving from a measuring object (12) is directed from the device. The sound absorption ability is further increased by utilizing a low-frequency cavity resonance between the projecting sound absorbents (20) and the substrate support (16). |
