Self-Fit vs. Professional-Fit Over-the-Counter Hearing Aids: A Randomized Clinical Trial.

Background: Over-the-counter hearing aids (OTC HAs) are approved for adults with mild-to-moderate hearing loss (HL) without professional assistance, but research comparing their effectiveness to professional-fit is limited. Purpose: We compared the effectiveness of OTC HA fittings between self-fit and professional-fit groups and examined how the group effects depend on the age, sex, technology proficiency, HL, and HA history. Research Design: At a university audiology clinic, 71 adults were randomly assigned to self-fit or professional-fit groups and fitted bilaterally with OTC HAs. The self-fit group used manual instructions. Participants underwent fitting, 1-month use, and outcome validation stages. Study Sample: Sixty-four native-English-speaking adults (32 per group) with mild-to-moderate sensorineural HL and normal cognitive and middle ear functions completed the study. The groups did not differ significantly in age. Data Collection and Analysis: The Quick Speech in Noise (QuickSIN) test, Abbreviated Profile of Hearing Aid Benefit (APHAB), and Speech, Spatial, and Qualities of Hearing Scale (SSQ12) questionnaires were completed at baseline and 1 month after fitting to assess aided benefit. Additional measures included Real-Ear Aided Gain/Output (REAG/O) and hearing thresholds from the OTC app and audiometer. Data on age, sex, HL, HA history status, and self-reported technology proficiency were also ascertained. Multivariate analysis of variance and repeated measures were conducted. Results: The professional-fit group had significantly higher REAG and REAO at 2000 Hz for all inputs, especially among individuals who were older, had greater HL severity, or reported higher technological proficiency. No significant differences in aided benefit were found between groups on the QuickSIN, APHAB, or SSQ12. However, the professional-fit group showed relatively greater benefit on the APHAB and SSQ12, and benefit on these measures declined significantly with age. The average threshold differences (app vs. audiometer) were within 10 dB, with some individual elevated thresholds (15-35 dB) at 500 Hz using the app. Conclusions: OTC HA could be an alternative option for listeners with mild-to-moderate HL. Professionals could facilitate the fitting process and provide more appropriate amplification acoustically. Clinical Relevance Statement: The comprehensive findings provide valuable insights into OTC fitting, aiding audiology professionals and patients in achieving better rehabilitation outcomes.