Damping the hearing aid frequency response: effects on speech clarity and preferred listening level.

Damped hearing aid frequency responses were compared with undamped responses to determine the effect of response smoothing on speech clarity and on gain received when the hearing aid was adjusted to the preferred listening level (PLL). Damping elements were located in the hearing aid's earhook. Three commercially available hearing aids, two bandwidths, and two speech input levels were evaluated in a completely crossed experimental design. Data were collected using a paired comparison method and 10 hearing-impaired subjects. Results indicated that the undamped frequency responses were judged to produce more clear, pleasant, natural sounding speech than the damped responses (p = .09). Although significant midfrequency peak reduction was achieved through earhook damping, the effects on gain at PLL were negligible.