| 摘要 |
1,173,657. Hearing aids. ELECTRIC & MUSICAL INDUSTRIES Ltd. 6 May, 1968 [9 May, 1967], No. 21475/67. Heading H4J. The case 1 (Figs. 1, 2) of an in-the-ear hearing aid is moulded so that a part of the external shape conforms to the shape of a part of the auricle. A separately formed resilient attachment 14, 15 is adapted to project into the auricular extension to form an acoustic seal between the case 1 and the user's ear. The attachment 14, 15 is preferably mushroomshaped and has an axial aperture. A sealing flange 13 is mounted between the case 1 and the attachment 14, 15 and a ring or sealing strip 12 fits round or partly round the case 1. The members 12, 13, 14, 15 provide an acoustic seal and combinations of different sizes with a fixed size case 1 enable the aid to be adapted to a variety of users. The members 12, 13, 14, 15 are of soft P.V.C. matched in colour to the case 1 which is of natural colour cellulose propionate plastics material. The case interior has a compartment 2 containing an earphone (not shown) for feeding sound into a tubular output orifice 16. A compartment 3 contains a microphone (not shown) and sound reaches it through an aperture (not shown) in a cover-plate 11. A compartment 4 contains a chassis 5 holding an amplifier comprising a volume control 6, resistors, capacitors and an integrated circuit 7. The volume control 6 projects through a slot (not shown) in the cover-plate 11. The coverplate 11 has a matt finish. A battery 8 is replaceable through a pivoted door 9. The flange 13 and/or ring 12 may be dispensed with (Figs. 4, 5, not shown). |
