In-ear hearing aid - has contoured end plate for utilising acoustic amplification of natural ear formation

摘要

The hearing aid has a microphone, an amplifier and a loudspeaker supplied via a battery, with a potentiometer for setting the required hearing level. The hearing aid has a moulded housing with an end plate which is matched to the ear for utilising the acoustic amplification of the ear formation and fitted within the ear, to prevent unhindered progression of the sound waves. Pref. the potentiometer setting control (4) and an On-Off switch are fitted at the end of a projecting rotary shaft (6). ADVANTAGE - Increased power factor for relatively small size.