Patent ID: 10798474

Abstract:
The waterproof sound-transmissive cover is characterized by providing a frequency response curve with a difference between a maximum sound pressure level and a minimum sound pressure level of 13.0 dB or less in the range of frequencies from 3 kHz to 8 kHz, and an insertion loss at 1 kHz of less than 14.0 dB, and said cover comprising: a porous film having (1) a water pressure resistance measured according to JIS L1092 water penetration test method B (high pressure method) of 20 kPa or more, and air permeability measured according to JIS L1096 method A (Frazier type method) of 3.0 cc/cm2·sec or more, and (2) a tensile strength measured according to ASTM standards D412 of 5.5N or more.