Predictability of the required frequency response characteristic of a hearing aid from the pure-tone audiogram

This paper examines the predictability of the optimal frequency response characteristic of a hearing aid from the shape of the pure-tone audiogram. The main data were derived from two studies, using 14 and 16 sensorineurally hearing-impaired ears, representing a wide variety of audiometric configurations. Optimal (required) frequency response slopes were estimated from most comfortable loudness levels for speech bands after finding that such responses were superior to ones derived from other procedures. The low (0.4 or 0.5 to 1.25 kHz), high (1.25 to 3 kHz), and total (0.4 or 0.5 or 3 kHz) slopes of the optimal responses were analyzed relative to the corresponding audiogram slopes. A moderately strong relationship was found between audiogram slopes and required response slopes (correlations averaged almost 0.6) and different studies agreed substantially regarding the formula describing that relationship. We conclude that it is justifiable to select the frequency response of a hearing aid from the pure-tone audiogram and that an appropriate formula would be more effective than providing a standard frequency response for all clients.