Preference For Combined Hearing Aid Signal Processing

Despite extensive technological advancements and evidence that hearing aids improve the quality of life of hearing-impaired listeners, the rate of hearing aid adoption has been disproportional to the prevalence of hearing-impairment among adults. Technologies directed at improving certain aspects of speech information also degrade other essential aspects of the signal. Moreover, there is limited research documenting perceptual outcomes when signal processing strategies function collectively as in real hearing aids. This project specifically addresses our need to understand how these signal processing parameters together influence listeners’ preferences. The specific aims of this project are two-fold. The first aim is to determine hearing impaired listeners’ preference for combinations of hearing aid signal processing. Adapting the principles of conjoint analysis, this project proposes an approach where listeners will make paired comparisons of sentences processed with some combination of strategies. A full-factorial design with three common signal processing strategies (two levels each) will be evaluated. In order to address ecological validity, low-context sentences will be presented at two different signal-to-noise ratios (SNRs). The second aim is to determine the relationship between hearing-impaired listeners’ preference for hearing aid signal processing and the resulting signal modification. Signal modification for all the conditions will be quantified using existing speech intelligibility/quality metrics and regressed against measured preference. It is expected that preference for signal modification will depend on the signal processing conditions. Further, preference for one form of signal processing depend on the strength of other forms of signal processing present in the signal and this effect will be modulated by the SNR. Results will inform optimization of hearing aid signal processing and clinical decision-making. Understanding listeners’ preferences can ultimately improve success with hearing aids. Future research will characterize individual variability in preferences and establish relationships with other perceptual outcomes.