A Changes of Loudness Growth as a Function of Hearing Threshold Level in Adults with Normal and Sensorineural Hearing Loss

Abstract

The purpose of this study was to examine changes in the most comfortable level (MCL) and the uncomfortable level (UCL) depending on hearing threshold level (HTL) by investigating loudness growth among persons with normal hearing (NH) and sensorineural hearing loss (SNHL) at 500 Hz and 3,000 Hz. Based on the results, this study intended to provide useful data to calculate gain or frequency response curve and SSPL90 or OSPL90 of hearing aid that was used by Koreans with hearing loss. The NH group consisted of 17 persons (17 ears) in total who had the pure tone threshold average of 20 dB HL or less and who were 23-33 years old (average: 27.9 years, SD: 4.0 years). The SNHL group consisted of 117 persons (161 ears) in total who had the HTL of 40-75 dB HL at 500 Hz or 3,000 Hz and who were 19-78 years old (average: 55.1 years, SD: 15.4 years). As for presented tone, 5% frequency-modulated tone was used at 500 Hz and 3,000 Hz. Based on the results of study by Allen (1990), loudness category (LC) for loudness growth test was divided to 7 LCs before the HTL of 40-75 dB for NH and SNHL was divided by 5 dB interval at 500 Hz and 3,000 Hz. The results of this study were as follows. First, at 500 Hz and 3,000 Hz, the MCL of NH was 51.5 and 56.8 dB HL while the UCL was 88.5 dB HL and 88.7 dB HL. Consequently, the MCL at 3,000 Hz was found to be higher by 5.3 dB (p < .05). Second, the MCL and the UCL of SNHL persons increased as a function of the HTL. However, slope of regression equation was low in the order of the HTL, the MCL and the UCL. Therefore, it was confirmed that dynamic range became narrow according to increase in the HTL. Third, the MCL showed the higher correlation with the HTL than the UCL. This study was meaningful in that the study intended to measure loudness growth of Koreans with NH and SNHL. The results of this study are expected to have influences on development of hearing aid fitting formula for Koreans with hearing loss.

Comparison of a Hearing Aid Fitting Formula Based on Korean Acoustic Characteristics and Existing Fitting Formulae

“…For the loudness, gains were determined to follow the normal loudness growth. Thus, reported data of loudness growth for Koreans who have SNHL (Park & Lee, 2013) was used for determining the most comfortable level (MCL) and uncomfortable level (UCL) across frequencies. The MCL and UCL values were calculated based on a patient's hearing threshold in a given frequency band and a frequency-dependent weighted factor (Park & Lee, 2013).…”

Change in Preferred Gain, Word Recognition Scores, and Sound Qualities as Hearing Aid Wearing Period

“…외이와 중이에 염증, 기형 등 특별한 문제가 없는 감각신경 성난청(sensorineural hearing loss, SNHL)은 청력역치레벨 (hearing threshold level, HTL) 그리고 일상생활에서 저하 된 의사소통 능력과 삶의 질 개선을 위한 보편적인 방법으로 기 도보청기(air-conduction hearing aid)의 착용을 고려할 수 있다 (Erler & Garstecki, 2002) 근으로 볼 수 있기 때문이다 (Kiessling et al, 1996;Park & Lee, 2013)…”