Comparing Self-Fitting Strategies for Over-the-Counter Hearing Aids: A Crossover Clinical Trial.

Importance: Fewer than 20% of US adults with hearing loss use hearing aids due to barriers like high cost. Over-the-counter (OTC) hearing aids offer a potential solution, incorporating self-fitting strategies via smartphone apps. Self-fitting strategies have been validated for Food and Drug Administration (FDA)-approved OTC hearing aids compared with prescription-based approaches. However, no direct comparative analysis exists between in situ audiometry and self-adjustment strategies using self-fitting OTC (OTC-SF) hearing aids.

Objective: To compare self-adjustment and in situ audiometry self-fitting strategies in OTC-SF hearing aids for adults with mild to moderate hearing difficulties.

Design settings and participants: A crossover, within-participant pseudorandomized clinical trial was conducted between July and November 2023. Twenty-eight participants were pseudo-randomly assigned to 1 of the 2 self-fitting strategies, and they experienced both interventions for 4 consecutive weeks.

Interventions: The self-adjustment group manually adjusted settings, including overall gain and spectral tilt, using Lexie B2 hearing aids, while the in situ audiometry group used Lexie B2 Plus hearing aids (Lexie Hearing by hearX Group), with an automated fitting based on in situ tests conducted through the app.

Main outcomes and measures: The primary outcome was Abbreviated Profile of Hearing Aid Benefit (APHAB). Secondary outcomes were International Outcome Inventory for Hearing Aids (IOI-HA), speech-in-noise tests (DIN and QuickSIN), and real-ear measurements (REMs). Measures were completed at baseline and after the 4-week field trial using each strategy.

Results: Twenty-eight participants (mean [SD] age, 60.2 [12.0] years) were included; 14 men and 14 women. Self-adjustment and in situ audiometry strategies produced no clinically meaningful differences across various outcome measures, including overall APHAB benefit (Cohen d = 0.2; 95% CI, -0.2 to 0.6) and overall IOI-HA satisfaction (Rosenthal r = 0.0; 95% CI, -0.3 to 0.2). Self-adjustment users reported higher satisfaction (Rosenthal r = -0.4; 95% CI, -0.6 to -0.1) and longer daily use (Rosenthal r = -0.3; 95% CI, -0.5 to 0.0) compared with those using in situ audiometry. No clinically meaningful differences were observed in speech-in-noise benefit and real-ear measurements.

Conclusion and relevance: In this clinical trial of OTC-SF hearing aids, self-adjustment and in situ audiometry strategies resulted in similar outcomes. However, self-adjustment may produce higher satisfaction and longer daily use, highlighting the potential advantages of active user involvement in the fitting process. Further investigation is needed for long-term outcomes.

Trial registration: ClinicalTrials.gov Identifier: NCT05782153.