| 摘要 |
PROBLEM TO BE SOLVED: To provide a whole sound transmission plate capable of achieving whole sound transmission performance, in particular, whole sound transmission performance in a major voice frequency band irrespective of use of holes having very small diameter. SOLUTION: This whole sound transmission plate has micropores having average diameter of openings of 1-2,000μm and passing through from a face on one side to a face on the other side in a hard plate, a rate of opening obtained by the micropores on the faces of the hard plate per hard unit area is 3-50%, and average distance between the micropores is 1.5-4 times average diameter of openings. COPYRIGHT: (C)2010,JPO&INPIT |
