디지털 보청기에서의 한국어 비선형 fitting formula

초록

In this study, we suggest new fitting formula to fit digital hearing aids (Korean nonlinear fitting formula, KNFF). The rationale is to maximize speech intelligibility of Korean. So we have adopted the NAL-NL1 (National Acoustic Laboratories’ nonlinear, version 1) developed to maximize speech intelligibility in NAL of Australia. Korean long term average speech spectrum (LTASS) is used in this formula. The insertion gain was modified to enhance the intelligibility of high frequency words in Korean. To verify effect of the new fitting formula, we performed speech discrimination test (SDT) and preference test using the hearing loss simulator from NOISH. As a result of the test, the SDT scores of the KNFF was more improved both in the case of the moderate hearing loss with severe loss on high frequency and in the case of the severe hearing than NAL-NL1. This result confirm that it was the effective way to increase gain of mid-high frequency bands and to decrease gain of low frequency bands in order to enhance the speech intelligibility of Korean.