The infrared light transmission hearing aid.

Recognizing the inherent weakness of the conventional hearing aid, we have developed a totally new design for hearing aids utilizing infrared (IR) light transmission. The hearing aid transmits the auditory message not as an acoustic wave, but as an infrared light beam. The invisible light beam carries the signal directly from a microphone near the speaker to the listener without any appreciable loss of level or fidelity, thereby providing true suppression of room noise. In preliminary tests, the IR aid has been shown to deliver intelligible sound under many noisy conditions where the conventional personal hearing aid is of little value. In this report, progress is reported in two related areas: (i) measurement of the hearing handicap of potential candidates for the IR aid, and (ii) engineering development of IR systems for personal and group hearing situations.