Efficacy and Effectiveness of Evidence-Based Non-Self-Fitting Presets Compared to Prescription Hearing Aid Fittings and a Personal Sound Amplification Product.

Abstract

In this study, we compare the efficacy and effectiveness of gain-frequency responses of evidence-based presets developed by our lab for over-the-counter hearing aids to conventional National Acoustic Laboratories' nonlinear fitting procedure, version 2 (NAL-NL2) gain-frequency response and to gain-frequency response of a personal sound amplification product (PSAP). We hypothesized that the hearing aids with our presets would perform better than a PSAP with poor frequency response and comparably to the hearing aid with NAL-NL2 frequency response. We used a single-blinded, randomized cross-over design to compare audibility, speech recognition, sound quality, listening effort, and subjective preferences in 37 participants in laboratory settings and following field trials. The presets developed in our lab showed comparable outcomes to the hearing aids with NAL-NL2 gain-frequency response in most measured domains. Performance with the presets was better than the PSAP gain-frequency response in the domains of listening effort and sound quality in laboratory testing and speech recognition in our real-world measures. We also found that most participants (54.05%) preferred our presets over the PSAPs and were willing to pay significantly more to purchase the hearing aids with our presets. Our evidence-based presets have better outcomes than a PSAP with a single, poorly suited frequency response while performing comparably to the clinical best-practice National Acoustic Laboratories condition.