The Impact of Hearing Loss and Hearing Aid Experience on Sound Quality Judgments

Abstract

The purpose of this experiment was to quantify potential differences in sound quality judgments from individuals with normal hearing, hearing loss but no hearing aid experience, and hearing loss and hearing aid experience. Normally hearing subjects (15), subjects with hearing loss but no hearing aid experience (15), and subjects with binaural hearing aid experience (15) rated the sound quality (0 to 100%) of continuous discourse recordings made with three binaural sets of hearing aids. The hearing aids represent a range of coherence function values from perfect coherence (assumed excellent sound quality) to poor coherence (assumed poor sound quality) with two input levels (70 and 90 dB SPL). The normally hearing and hearing-impaired group with no hearing aid experience revealed identical sound quality preferences at the 90 dB SPL input level that were consistent with the physical measure of sound quality. These two groups did not show a particular preference for either the soft or loud input levels, whereas the experienced hearing aid users rated sound quality significantly higher for the loud input level regardless of type of hearing aid and sound quality as defined by the physical measurement. These results should affect the use of experienced users in the evaluation of the sound quality of hearing aid circuitry for development purposes and reliance on individual sound quality judgments when trying to fit previous users with new hearing aid circuitry.