Two Hearing Aids or One? A New Randomized Trial Measures the Real-World Benefit

A randomized clinical trial of 275 older adults found that one hearing aid and two hearing aids both delivered meaningful benefit, with the two-aid group reporting a modest additional advantage.

Age-related hearing loss is among the most common chronic conditions of later life. It usually develops gradually in both ears at once, is sensorineural in origin, and most often sits in the mild to moderate range. Left unaddressed, it is linked with strain on communication, social withdrawal, lower mood, and growing concerns about cognitive and physical health.

For decades, the default advice in hearing care has been that two affected ears deserve two hearing aids. Yet one of the most common questions patients ask is whether they really need the second device, and rigorous randomized evidence comparing one aid against two has been thin. A new trial published in JAMA Otolaryngology, Head & Neck Surgery set out to answer that question directly.

Background: Why the Researchers Looked at This

Hearing aids are the standard treatment for age-related hearing loss, and because the condition typically affects both ears, clinicians usually recommend a bilateral fitting. What has been missing is high-quality evidence showing how much extra benefit that second device actually provides. The study authors note that data demonstrating the effectiveness of unilateral or bilateral hearing aids as the standard treatment have been lacking.

The question matters for practical reasons. A second hearing aid adds cost, and some wearers find managing one device easier than two. Sound localization, the ability to tell where a sound is coming from, and understanding speech in background noise are both thought to depend on input from the two ears together, which is the theoretical case for a bilateral fitting. Whether those advantages translate into benefit that wearers themselves notice in daily life is the question this trial was designed to test.

How the Study Was Done

The researchers ran a single-blinded, parallel-group randomized clinical trial at audiology clinics of Duke University Health System and Vanderbilt University between 2021 and 2024. Participants were adults aged 50 or older with age-related hearing loss who were seeking hearing aids and had less than 3 months of any prior hearing aid use.

Each participant was randomly assigned to receive either one hearing aid or two. All devices were commercially available prescription receiver-in-the-canal hearing aids. The primary outcome was hearing aid benefit at 3 months, measured with the Abbreviated Profile of Hearing Aid Benefit, or APHAB, a standardized questionnaire in which wearers report how much difficulty they experience in everyday listening situations. Benefit was defined as the change between the unaided baseline score and the aided score at 3 months, and the analysis followed the intention-to-treat principle.

What the Researchers Found

A total of 275 participants took part, 148 of them women (53.8 percent), with a mean age of 70.9 years. The unilateral group included 136 people and the bilateral group 139.

Both groups improved substantially. The mean APHAB benefit score was 14.41 points in the unilateral group and 19.74 points in the bilateral group. In plain terms, people wearing a single hearing aid reported clearly better everyday hearing than before treatment, and people wearing two reported more improvement still.

The between-group difference was about 5.3 points in favor of the bilateral fitting, with a 95 percent confidence interval spanning roughly 1.8 to 8.8 points, a statistically significant result. The authors are careful to note, however, that it is not clear whether a gap of that size crosses the threshold of clinical meaningfulness, while the improvement within each group was individually meaningful.

What It Means for People with Hearing Loss

The most encouraging message is that treatment worked in both configurations. For people who cannot or prefer not to wear two devices, whether for reasons of cost, comfort, dexterity, or simple preference, a single well-fitted hearing aid still produced a solid, meaningful improvement in self-reported everyday hearing.

At the same time, the trial provides the clearest randomized evidence to date that two hearing aids offer, on average, a modest extra benefit over one for the typical bilateral, mild to moderate hearing loss of aging. The authors frame the results as informing, but not yet establishing, a standard-of-practice recommendation for bilateral fitting. The choice can stay personal, guided by budget, lifestyle, and listening needs.

A Modest Edge for Two Ears, and Options Beyond the Clinic

The devices in this trial were prescription receiver-in-the-canal hearing aids fitted at university clinics. The same general design is now also available among FDA-OTC hearing aids, a category created for adults with mild to moderate hearing loss, the very degree of loss this trial studied.

Panda Quantum is one such device, a 16-channel receiver-in-the-canal FDA-OTC hearing aid with adaptive noise reduction aimed at clearer speech in noisy environments. It runs 20 hours per charge, its case stores three additional full charges for 80 hours of total use, and it streams Bluetooth audio for calls, TV, and music. It comes with a 5-year warranty and a 45-day trial that begins when the device arrives.

Quantum also includes an optional app-based self-hearing test: the companion app can run a frequency-specific test through the aid itself and personalize gain and frequency response to the wearer's hearing profile. The app and the test are optional, and the device works out of the box without them. One caveat worth keeping in mind: OTC devices are approved for mild to moderate loss, and severe or profound hearing loss still benefits most from a clinical fitting.

Limitations of This Research

The primary endpoint came at 3 months, so the trial cannot say whether the gap between one and two hearing aids widens, narrows, or disappears with longer use. The main outcome was self-reported, which suits a question about perceived benefit but leaves open how the two fittings compare on objective measures such as speech understanding in noise. Participants were people actively seeking hearing aids at two academic medical centers, which may limit how far the findings generalize.

The authors themselves stress that the statistically detectable difference between groups may not reach clinical meaningfulness. Funding sources and conflicts of interest were not detailed in the abstract available through PubMed.

Where This Leaves Us

This trial replaces decades of assumption with randomized data: both one and two hearing aids genuinely help people with age-related hearing loss, and two help somewhat more on average. For anyone weighing the choice, the results support starting treatment either way rather than delaying, and they give clinicians and wearers honest numbers to talk through together.

Smith SL, Ricketts TA, Kilpatrick KW, North R, Bettger JP, Coles T, Eberts S, Peskoe SB, Francis HW, Toth H, Dillon W, Thompson L, Branscome K, Walker A, Rockhold FW. Unilateral and Bilateral Hearing Aids for Age-Related Hearing Loss: A Randomized Clinical Trial. JAMA Otolaryngology, Head & Neck Surgery. 2026. Retrieved from PubMed. https://doi.org/10.1001/jamaoto.2026.2401