Performance of Individual Hearing Aids Utilizing Microphone and Induction Coil Input
Richard J. Sung, William R. Hodgson · Journal of Speech and Hearing Research · 1971
Physical measurements of gain, maximum power output, frequency response, and harmonic distortion were made on each of two body-type hearing aids on both the microphone and induction coil settings. In addition, we investigated speech intelligibility through each aid, for both acoustic and magnetic input, using 32 normal-hearing subjects. Our findings indicated that different hearing aids provide different sensitivity for loop induction. For a given hearing aid, physical characteristics varied between the microphone and the telephone coil settings. The intelligibility of speech produced by a given mode of signal input, either microphone or telephone coil, was dependent on physical characteristics of the hearing aid. The usable high-frequency response and the configuration of the response curve in the region of 1500 to 3000 Hz appeared to be associated with the intelligibility of monosyllabic words.