One trial has compared an over-the-counter hearing aid with an audiologist fitting

Over-the-counter hearing aids appear to work for the narrow group they are sold to, on the strength of one randomised trial: 64 adults with self-perceived mild to moderate hearing loss showed no meaningful difference at six weeks between a self-fitted OTC device with remote support and the same device fitted by an audiologist to verified prescriptive targets [s2]. That is a genuine result and a very small evidence base. It is also the only head-to-head randomised comparison of its kind, and it tested a single commercially available product [s2].

What the category is, and what it deliberately excludes

The US Food and Drug Administration created the over-the-counter hearing aid category for adults aged 18 and older with perceived mild to moderate hearing loss, effective 17 October 2022 [s1]. OTC hearing aids are air-conduction devices requiring no implantation or surgery, sold in stores and online without the supervision, involvement or prescription of a licensed health care professional [s1]. They must allow users to control the device settings and customise them through tools, tests or software [s1]. Within the category, the FDA distinguishes legacy and wireless devices with basic features such as volume control and preset programs from self-fitting devices offering greater customisation through hearing tests, software and smartphone apps [s1].

The exclusions are as load-bearing as the inclusions. OTC devices are not intended for severe or profound hearing loss, because they are limited in their maximum output and may not provide adequate benefit at those levels [s1]. Anyone under 18 requires a prescription device and, in the FDA's framing, specialised care [s1]. And the regulatory definition of a prescription hearing aid is now residual: any hearing aid that is not an OTC hearing aid [s1].

The access argument behind the rule is straightforward. Close to 30 million adults in the US have some degree of hearing loss, and only about one-fifth of those who could benefit from a hearing aid seek intervention [s1].

The trial

The comparison trial ran between 14 April and 29 August 2022 — before the category formally opened — and randomised 68 adults with self-perceived mild to moderate hearing loss to a self-fitting group or an audiologist-fitted group, both using the same commercially available self-fitting OTC device [s2]. The self-fitting participants set the devices up using the manufacturer's instructional material and smartphone app; the audiologist-fitted participants had theirs programmed to National Acoustics Laboratories nonlinear version 2 prescriptive gain targets with real-ear verification [s2].

Both groups first completed a two-week take-home trial with no support at all, after which fine-tuning became available — remotely on request for the self-fitting group, and from the audiologist for the other — followed by a further four-week trial [s2]. The primary outcome was self-reported benefit on the Abbreviated Profile of Hearing Aid Benefit; secondary measures included the International Outcome Inventory for Hearing Aids and two speech-in-noise tests [s2].

Sixty-four participants formed the analytic sample: 33 men (51.6%), mean age 63.6 years (SD 14.1), 32 in each group, with no significant difference in age or four-frequency pure-tone average [s2]. After the unsupported two-week period the self-fitting group had a modest advantage on the two self-report measures — Cohen d = −0.5 (95% CI −1.0 to 0) on the APHAB and effect size r = 0.3 (95% CI 0.0 to 0.5) on the IOI-HA — but not on speech recognition in noise [s2]. By the end of the six-week trial, no meaningful differences were evident between the groups on any outcome measure [s2].

Note where both confidence intervals sit. The APHAB interval reaches exactly zero and the IOI-HA interval starts at zero, so even the early advantage is compatible with no difference. The finding that survives is the one at six weeks: equivalence, not superiority.

What the wider device literature adds, and where it gets confused

A 2026 systematic review and meta-analysis pooled 33 randomised controlled trials of air-conduction hearing devices in 4,471 adults with mild-to-severe hearing loss [s3]. It is useful mainly for what it reveals about the state of the field. Pooled estimates could be derived from only a subset of trials because of limited reporting; heterogeneity exceeded I² of 80%; and roughly 81% of the outcomes assessed were self-reported, with very limited assessment of cognitive or neurophysiological domains [s3]. Nine studies reported adverse events, with only one device-related incident [s3].

Against placebo, hearing aids produced a small pooled effect (Hedges's g of approximately 0.37), which the authors note was driven largely by trials including participants with comorbid Alzheimer's disease [s3]. Personal sound amplification products showed a pooled medium effect against no intervention (g of approximately 0.42) [s3]. In head-to-head comparisons based on two trials, hearing aids showed a large pooled advantage over other devices including smartphone hearing aid applications and extended-wear hearing aids (g of approximately 0.88) [s3].

Personal sound amplification products are not OTC hearing aids, and conflating them is the most common error in consumer coverage of this market. PSAPs are amplifiers, not devices regulated as hearing aids; the FDA's OTC category applies to hearing aids intended to address perceived mild to moderate hearing loss and carries labelling requirements that consumer amplifiers do not [s1]. Evidence about one says little about the other.

The honest summary

For an adult who has self-assessed a mild to moderate hearing difficulty, one trial supports the proposition that a self-fitting OTC hearing aid with remote support performs comparably to the same device fitted by an audiologist after six weeks [s2]. Beyond that, the evidence thins fast: long-term outcomes, comparisons across the many products now on sale, and performance in people whose actual hearing loss turns out to be worse than they perceived are all unstudied. The FDA's own guidance is that suspected severe or profound loss warrants a licensed professional, because the devices are output-limited by design [s1].

This article describes regulatory information and published trial results and is not medical advice. Sudden hearing loss, one-sided loss, pain, discharge or dizziness are reasons to see a clinician rather than to buy a device.