Importance: Over-the-counter (OTC) hearing aid options have expanded rapidly since the FDA created a category permitting their sale. Yet, evidence on clinical effectiveness is limited.

Objective: To systematically review and meta-analyze the clinical effectiveness of self-fitting OTC hearing aids compared with professionally fitted devices.

Data sources: PubMed, Scopus, Web of Science, FDA premarket submission [510(k)] and new device De Novo databases, and ClinicalTrials.gov were searched in March 2025, with an updated search in August 2025. Reference lists were reviewed, and manufacturers were contacted for unpublished data. After excluding duplicates, 712 records were screened.

Study selection: Abstract screening, full-text review, and risk of bias assessment were performed by two reviewers. Eligible studies compared FDA-cleared (i.e., similar to existing marketed products) self-fitting OTC hearing aids or software with professionally fitted devices in adults using a field trial.

Main outcomes and measures: Primary outcomes included patient-reported benefit and speech recognition in noise. Other outcomes  were satisfaction ratings and real-ear verification. A random-effects meta-analysis using Hedges’ g was performed.

Results: From 712 records, 24 were included, representing 15 unique studies with 774 participants (739 analyzed). Most were short-term field trials (10 days-8 weeks) comparing a self-fitting OTC hearing aid to a professional-fit of the same device. Pooled analysis of the Abbreviated Profile of Hearing Aid Benefit (APHAB) showed no significant group difference (Hedges g = -0.05; 95% CI -0.19 to 0.09). Similarly, meta-analyses of the Speech, Spatial, and Qualities of Hearing Scale-12 (SSQ-12; g = 0.01; 95% CI -0.33 to 0.36), International Outcome Inventory for Hearing Aids (IOI-HA; g = 0.11; 95% CI -0.35 to 0.59), and Quick Speech-in-Noise test (QuickSIN; g = 0.03; 95% CI -0.22 to 0.28) demonstrated no meaningful differences between self-fitting and professionally fitted devices. Risk of bias was high for 6 studies and moderate for 8.

Conclusions and relevance: Self-fitting OTC hearing aids provide outcomes comparable to professionally fitted OTC devices for adults with mild to moderate hearing loss. Evidence is limited by small samples, use of the same device as comparator and industry sponsorship, which may bias reporting and publication. Larger independent trials are needed, but current findings support their role in expanding access to hearing care.