Improvements in Hearing-Aids of the kind worn on the Users' Heads

摘要

A hearing aid housing, which fits behind the user's ear or is in the form of a spectacles frame, accommodates a microphone, has a forward opening through which sound waves reach the microphone mainly from the direction in which the user is facing, and a rearward opening and a channel through which sound waves reach the microphone from the direction opposite to that in which the user is facing. Two back-to-back microphone transducers 10, 11 (Fig. 1) are in a housing 7. An opening 8 for transducer 10 is such that when the aid is worn it points forward. An elastic tube 12 leads from an opening 13, facing in the opposite direction, to transducer 11. The output leads from the transducers 10, 11 are connected to an amplifier 2 such that sound entering through opening 8 is reproduced at a greater amplification than sound entering through opening 13. In a second embodiment (Fig. 2, not shown), a single microphone transducer 14 (Fig. 3) is used together with a front opening 8 and rear tube 12. The transducer comprises a casing 15 and cover 16 having apertures 23 and 17 respectively. A diaphragm 18 is coupled to a magnet system 20. A second diaphragm 21 is coupled with the diaphragm 18 only through the air enclosed in a chamber 22.