OTC Hearing Aid Research Is Shifting From Opinion to Evidence, New Analysis Finds

A new proof-of-concept analysis of three decades of published research suggests the scientific conversation around over-the-counter hearing aids has matured from commentary and opinion into measurable, empirical study since U.S. regulators created the category.

When the U.S. Food and Drug Administration's over-the-counter hearing aid category took effect in October 2022, it ended years of policy debate about whether adults with milder hearing loss should be able to buy hearing aids directly, without a prescription or a clinic visit. What was less clear was whether the research community would follow the market.

A research team spanning Hong Kong, the United States, the Netherlands and South Africa set out to answer that question with data. Their study, published this week in the International Journal of Audiology, maps how the published literature on over-the-counter hearing aids changed before and after the FDA rule, and what topics researchers still tend to overlook.

Background: Why the Researchers Looked at This

For most of the past three decades, writing about over-the-counter hearing aids was dominated by position papers, editorials and policy commentary. Advocates argued that direct-to-consumer devices could lower cost and access barriers for the millions of adults with untreated hearing loss, while critics worried about safety, fitting quality and the loss of professional oversight. Once the FDA finalized its rule, the debate was in one sense settled, and the question became empirical: how do these devices actually perform, and who uses them?

The authors wanted to know whether the character of the research literature changed alongside the regulation. To do that at scale, they combined two methods. Bibliometrics is the statistical study of publications themselves, such as when and where papers appear. The team also used large language models, the technology behind modern AI assistants, to read and annotate study abstracts along predefined dimensions, with human raters screening the articles first.

How the Study Was Done

The researchers identified 106 articles related to over-the-counter hearing aids indexed in the Web of Science database. Human raters screened each article, and the set was divided into a pre-implementation group of 45 papers published from 1995 through 2022 and a post-implementation group of 61 papers from 2023 through 2026. The fact that the post-rule group is already larger, despite covering barely four years against nearly three decades, is itself a signal of accelerating interest.

Each abstract was then annotated using a structured framework called GABRIEL, with large language models scoring the papers on eight predefined dimensions, such as how strongly they emphasized older adults, the consumer perspective, or mild-to-moderate hearing loss. The two time periods were compared statistically, with corrections applied to guard against false positives from multiple comparisons, and the team checked that different AI models produced consistent annotations.

What the Researchers Found

The clearest shift was in the type of evidence being published. Before the FDA rule, the literature was dominated by commentary. Afterward, empirical research took over, meaning studies that collect and analyze actual data from devices and users. This change was statistically significant, with a chi-square value of 13.32 and a moderate effect size.

Among the eight content dimensions, only one reached adjusted statistical significance in the primary analysis: a reduced emphasis on older adults in the post-implementation period. In other words, newer papers frame over-the-counter devices less exclusively as products for seniors. Attention to the consumer perspective and to mild-to-moderate hearing loss both increased directionally, though the consumer finding reached significance only in an exploratory sensitivity analysis.

Timing patterns suggested the reorientation of the field did not begin at market entry in late 2022. Instead, descriptive trends were consistent with the shift starting during the 2017 to 2022 period, when the enabling legislation passed and the FDA was drafting its rules. Researchers, it seems, started changing course as soon as the policy direction became clear.

The analysis also identified persistent blind spots. Research on low-income and underserved populations remains scarce, and publication activity is geographically lopsided, concentrated in a handful of countries despite hearing loss being a global concern.

What It Means for People with Hearing Loss

For consumers, the headline is reassuring: over-the-counter hearing aids are no longer just a policy idea being argued about in journals. They are now the subject of real empirical study, which over time should give buyers better independent information about how devices perform in daily life.

The softening of the older-adult framing also matters. Hearing loss affects working-age adults, and a research agenda that treats direct-to-consumer devices as tools for a broad population, rather than a niche product for the very old, better reflects who actually experiences mild-to-moderate hearing difficulty.

Self-Fitting OTC Hearing Aids Are Now the Subject of Real-World Study

Because this study tracks a research field catching up with a consumer reality, it is worth noting what that reality looks like. FDA-OTC hearing aids were created precisely to serve the growing, not exclusively elderly, population the newer literature describes, and self-fitting OTC hearing aids are a large part of that shift.

Panda Air is one example of the category these researchers are now studying empirically. It is an earbud-style device with 16-channel processing and multi-band adaptive noise reduction, closer in feel to modern earbud-style hearing aids than to the devices of a decade ago. An optional companion app can run a frequency-specific hearing check through the aid itself and personalize gain to the user's hearing profile, though Air also works out of the box without the app or the test. A fast-charge case provides 60 hours of total use, and the device carries a 5-year warranty with a 45-day trial that starts when it arrives.

One caveat the literature consistently supports: the OTC category is approved for adults with mild-to-moderate hearing loss, and people with severe or profound loss still benefit most from clinical fittings. Details on Air are at pandahearing.com/products/panda-air.

Limitations of This Research

The authors are careful to describe this as a proof of concept. The findings show temporal associations within one database, Web of Science, and cannot prove the FDA rule caused any of the observed shifts. The AI-assisted annotations measured patterns in abstracts rather than expert-validated readings of full papers, and the sample of 106 articles is modest.

Readers should also note that the first author is affiliated with Orka Health, a hearing device company, alongside an academic appointment. The paper itself flags the field's remaining gaps, particularly the shortage of research on low-income and underserved groups.

Where This Leaves Us

Four years into the OTC era, the science is starting to do what the policy debate could not: replace predictions with measurements. The next phase, if the researchers' recommendations are heeded, will test how well direct-to-consumer hearing technology serves the people with the fewest alternatives, in the places where hearing care is hardest to reach.

Mo C, Manchaiah V, Wasmann JWA, Wang S. From policy debate to empirical evidence: a proof-of-concept bibliometric and LLM-assisted abstract-level content analysis of OTC hearing aid research before and after FDA regulation. International Journal of Audiology. 2026. Retrieved from PubMed. https://doi.org/10.1080/14992027.2026.2720841