Variability of Preference-Based Adjustments on Hearing Aid Frequency-Gain Response

Although users can customize the frequency-gain response of hearing aids, the variability in their individual adjustments remains a concern. This study investigated the within-subject variability in the gain adjustments made within a single self-adjustment procedure.

Two experiments were conducted with 20 older adults with mild-to-severe hearing loss. Participants used a two-dimensional touchscreen to adjust hearing aid amplification across six frequency bands (0.25-8 kHz) while listening to continuous speech in background noise. In these two experiments, two user interface designs, differing in control-to-gain map, were tested. For each participant, the statistical properties of 30 repeated gain adjustments within a single self-adjustment procedure were analyzed.

When participants made multiple gain adjustments, their preferred gain settings showed the highest variability in the 4- and 8-kHz frequency bands and the lowest variability in the 1- and 2-kHz bands, suggesting that midfrequency bands are weighted more heavily in their preferences compared to high frequencies. Additionally, significant correlations were observed for the preferred gains between the 0.25- and 0.5-kHz bands, between the 0.5- and 1-kHz bands, and between the 4- and 8-kHz bands. Lastly, the standard error of the preferred gain reduced with an increasing number of trials, with a rate close to being slightly shallower than would be expected for invariant mean preference for most participants, suggesting convergent estimation of the underlying preference across trials.

Self-adjustments of frequency-gain profiles are informative about the underlying preference; however, the contributions from various frequency bands are neither equal nor independent.

https://doi.org/10.23641/asha.28405397.