Difference Between the Preferred Gain and the NAL-NL2 Gain in Korean Hearing Aid Users

Abstract

Background and Objectives The purpose of this study was to compare the preferred gain and the National Acoustic Laboratories Nonlinear 2nd edition (NAL-NL2) gain value in Korean language hearing aid users.Subjects and Method In this retrospective study, preferred gain and NAL-NL2 gain data were obtained from 199 monaural hearing aids users who were satisfied with their hearing aid devices. The gain value data were collected from three different sound levels at various frequencies. Several factors were also evaluated to determine a potential impact on the preferred gain.Results The preferred gain was significantly higher than the NAL-NL2 target gain (p=0.01). This difference was highest with the gain measured with a medium-level sound (65 dB) with 1 kHz tone. There was a tendency of reduced preferred gain with the increased age of the participant (p=0.049).Conclusion The results indicate that Korean hearing aid users require more gain than the NAL-NL2 target gain. Linguistic characteristics, age, degree of hearing loss, and many other factors may be implicated in this result.