Comparing 2-cc Coupler Gain of Monaural Fitting withNon-Linear Fitting Formulas for Elderly Korean with SNHL

Abstract

Comparing 2-cc Coupler Gain of Monaural Fitting with Non-Linear Fitting Formulas for Elderly Korean with SNHL Kyoung Won Lee Jae Hee Lee and Jung Hak Lee Department of Audiology, Hallym Institute of Audiology & Speech Pathology, Hallym Institute of Advanced International Studies, Seoul, Korea, Graduate Program in Audiology, Hallym University, Chuncheon, Korea, Department of Speech and Hearing Sciences, Indiana University, Indiana, U.S.A Since there have been few studies on comparison of spectral and temporal characteristics between Korean and English speech sounds, research to date may not provide a consensus on the effectiveness of the coupler gains specified by the fitting formulas of NAL-NL1 to Korean hearing-impaired listeners. The two goals of this study were:1) to determine the coupler gains preferred by hearing-impaired listeners as a function of the input level;and 2) to compare the Korean preferred coupler gains with the coupler gains from NAL-NL1 that are based on English speech sounds. Eighteen hearing-impaired listeners (10 females and 8 males) with sensorineural hearing loss served as subjects. The ages of the subjects ranged from 47 to 88 years (M=67.9 yr, SD=8.7 yr) and their pure tone averaged (PTA) thresholds among 500, 1,000, 2,000, 4,000 Hz were between 42.5 and 75.0 dB HL. To avoid no preference for hearing-aids gains, the preferred coupler gains were examined at least after the three times of hearing-aids adjustments. The preferred coupler gains were measured at the frequencies between 250 and 4,000 Hz, with the conversational level sounds. Results showed that the Korean preferred coupler gains were lower than the coupler gains transferred from the fitting formulas of NAL-NL1, with greater differences in the frequencies below 1,500 Hz. These differences should be considered when fitting the hearing aid for the Korean hearing-impaired.