Future Implications for Implantable Hearing Aids

Abstract

The procedure for testing implantable-type hearing aids has been developed so as to utilize laboratory animals as well as the human. In the case of laboratory animals the test consists of measuring the ac cochlear potentials of the inner ear when that ear is activated by the implantable hearing aid. In the same manner distortion production is evaluated. The same procedure has been utilized to produce tapes of speech discrimination material when the animal in question had known damage to its inner ear. The speech discrimination tapes were recorded when the ear was activated by the best possible acoustical drives and also when the ear was activated by the implantable hearing aid. These tapes were then used to test the speech discrimination ability of young normal hearing adults. The implantable device produced 16% better speech discrimination. The speech discrimination ability of sensory neural impaired adults were tested using both acoustic and the implantable aid deliveries. The possible advantages of the implantable hearing aid are: (1) absence of ringing feedback; (2) possibility of improved speech discrimination in competing background noise; (3) and improved efficiency of delivery.