Comparison between Preferred Gain and Nal-Nll prescribed Gain Formulae in Naive Adult Hearing Aid Users

Abstract

The aim of the present study was to find the deviation in gain 'parameters, at three different input levels (soft, moderate and loud level) between preferred and prescribed (NALNL-1) fitting strategy in naive hearing aid users. The study included 33 participants in the age range of 30 to 80yrs, with mild to severe cochlear hearing loss and using digital BTE hearing aid. The results of the present study revealed. the gain preferences relative to NAL-NLI is different for different degree of hearing loss. Individuals with mild to moderate hearing loss preferred 3-4 dB lower whereas individuals with moderately severe and severe hearing loss preferred 4-8 dB higher gain than. that prescribed by NAL-NLI. The preferred gain differences relative to NAL-NLI across frequencies revealed greater deviations in mid frequencies than in low and high frequencies and increased with increase in degree of hearing loss. To conclude, Indian population requires higher gain at mid frequencies compared to western population for individuals with moderately severe and severe hearing loss.