A Comparative Study Of Physical Characteristics Of Hearing Aids On Microphone And Telecoil Inputs

The variations of sensitivity and frequency response of telecoil input on 32 commercially available body-type and behind-the-ear hearing aids were investigated. The differences in response between the microphone and the telecoil input were also examined. Findings indicate that (1) given aids have different sensitivity and frequency response for telecoil vs. microphone operation, (2) the telecoil, in general, provides a better low-frequency response than the microphone input, and (3) aids with similar responses on acoustic input may produce different responses on magnetic input. These findings further emphasize the importance of knowing the performance characteristics of the hearing aid operating on its telecoil input in order to avoid inappropriate hearing aid selection.