| 摘要 |
A thin metal sheet (10) for use in the manufacture of acoustic materials is provided with a multitude of small openings (11) therethrough, said openings being distributed substantially uniformly over the sheet's surface whereby the sheet has an acoustical flow resistance in the range of 10-300 rayls. The sheet can be used for example in the manufacture of acoustic tiles wherein an air chamber (16) is enclosed between the sheet (10), a base sheet (14) and side walls (12). |
