Optimum Speech Level in Case with Sensorineural Hearing Loss

Abstract

Optimum speech level is defined by the newly published International Standard of Speech Audiometry ISO8253-3 as the speech level at which maximum speech discrimination score is obtained. In this study, to estimate optimum speech level in cases with sensorineural hearing loss under the standard condition of speech audiometry by the use of 67-S monosyllable list, the results of speech discrimination test obtained from 350 ears of clinical cases were analyzed. They were classified into seven groups according to the degree of hearing loss in 10dB-step. In each group, the number of ears, in which every 5dB supra-threshold level was optimum speech level and non-optimum speech level, were accumulated. And the ratio of ears with optimum speech level against non-optimum speech level was analyzed. Then, we considered that the level at which the ratio was maximum number is most probably the optimum speech level. It was 50dB in sensation level in the group of ears with mean hearing threshold level at the level of 10dB, and decreased about 5dB with every 10dB of the hearing threshold level increased. These results may be useful on choosing test levels in speech audiometry and hearing aid fitting.