| 摘要 |
1,179,692. Deaf-aid sets. ELECTRIC & MUSICAL INDUSTRIES Ltd. 9 Aug., 1967 [19 Aug., 1966], No. 37148/66. Heading H4J. A hearing aid adapted to sit in the ear of a user has a resilient projecting ring or bead adapted to press on the inner surface of the outer ear so as to prevent acoustic feedback from the earphone to the microphone. As shown the aid is enclosed in a casing 2 of acrylic resin moulded to fit the ear of a particular user. A projecting bead 6 of silicone rubber is cast in situ in an undercut groove extending around the casing adjacent the microphone aperture. In another form (Fig. 4, not shown) a standard size aid having snap on, flexible earpiece extension as described in Specification 1,173,657, the casing has a projecting bead which extends most of the way round the casing and is interrupted to allow for a door through which the battery may be replaced. |
