Abstract
The guidelines of the test for evaluating the necessity of fitting a hearing aid (2008) proposed by Japan Audiological society states that the method to calculate the gain is based on the frequency response curve. The purpose of this study was to compare the gain calculated from the frequency response curve with the functional gain. The subjects were fifty-two adults (23 males and 29 females) with hearing loss. We compared them at five frequency points (250, 500, 1000, 2000, and 4000Hz) according to the guidelines. At each frequency, the average values had a significant correlation between the two gains. No significant differences were found between the gains at the 250, 500 and 1000Hz. The differences at 2000 and 4000Hz were, however, statistically significant. The functional gain at 2000Hz was 7.6dB higher than the gain calculated from the frequency response curve. Considering the errors of audiometric tests, the method of calculating the gain based on the frequency response curve may be acceptable as an assessment tool for hearing aid fitting.
