New Study Supports Hearing Loss as a Major Factor for People Already at Risk for Dementia

A new study involving a large, community-based sample of adults over 65 who were already at risk for dementia suggests that up to 32% of dementia cases over 8 years in this population may be attributable to clinically significant hearing loss—a strikingly higher estimate than those reported in previous U.S. studies. The findings highlight the growing recognition of hearing loss as a potentially modifiable risk factor for cognitive decline. They also raise new questions about the use of self-reported hearing loss (as opposed to actual audiometric measurements) in both research and public health strategies.

The study, “Population Attributable Fraction of Incident Dementia Associated with Hearing Loss,”¹ was published in today’s edition of JAMA Otolaryngology–Head & Neck Surgery. Some of its authors were previously involved in the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study.

The ACHIEVE study, published in 2023, followed two divergent groups of older adults for 3 years: about three-quarters were newly recruited from the community and were generally healthy, while the remaining quarter came from the Atherosclerosis Risk in Communities (ARIC) study—a separate study group followed for 8 years who tended to have multiple risk factors for dementia, such as lower education levels, cardiovascular problems and diabetes. The ACHIEVE study found that providing hearing-impaired members of the ARIC group with professionally fitted hearing aids led to a 48% reduction in cognitive decline over 3 years; however, hearing intervention had little effect on the healthier population relative to dementia (although it did improve other aspects like social engagement and depression).

How much of the overall dementia burden might be reduced by addressing hearing loss?

While the ACHIEVE study findings suggest that hearing interventions may help prevent dementia in some older adults, this new research asks, How much of the overall dementia burden might be reduced by addressing hearing loss in the at-risk (ARIC) population? The study also examined whether the potential for prevention differed by age, sex, or race.

The new study seeks to estimate the population attributable fraction (PAF), or the proportion of dementia cases that might be prevented if hearing loss were eliminated. The researchers compared results using objective hearing tests and self-reported hearing status because prior studies that relied on self-reporting may have significantly underestimated the true prevalence and impact of hearing loss.

They found that self-reported hearing loss, which is commonly used in large-scale studies and surveys, significantly underestimated the true prevalence of clinically significant hearing loss, especially in older age groups. In fact, among adults ages 70+, self-reporters misclassified their hearing ability in more than 70% of cases—which in turn suggests subjective measures may fail to capture the full scope of hearing-related dementia risk.

“People can’t tell you what they can't hear,” says audiologist Douglas Beck, AuD, an expert on hearing loss and cognition who was not involved in the study. “Hearing is just perceiving or detecting sound; listening is making sense of sound. So even patients who are almost deaf—people who have moderately severe or even severe hearing loss—can often hear if you’re in a quiet room and speaking directly in front of them. They might tell you they can hear, but what they can't do is tell you what they can't hear.

“With vision, when you reach about age 45 or 50, you realize you can't read fine print anymore; everything is blurry, and so you make an appointment to get your eyes tested,” says Beck. “But in hearing, there's no real equivalent. You can't detect what you can't hear, so you’re left with comments from your spouse or friends that are easy or convenient to discount. So instead, what people start to think is, “Oh my gosh, when I was a kid, everybody had to enunciate clearly.”

Almost one-third of dementia cases in at-risk population linked to hearing loss

The estimated population attributable fraction (PAF) of 32%—or the proportion of dementia cases that might not have occurred if hearing loss were eliminated—far exceeds previous U.S. estimates, which have typically ranged from 2% to 19%.

The authors say several factors likely account for this difference. Earlier studies often relied on self-report data, which underestimated prevalence. Others used formulas for calculating PAFs that can be biased downward when numerous risk factors are present. Additionally, studies that used audiometric data typically found only a weak association between mild hearing loss and dementia.

This new estimate also surpasses the 8% figure reported by the influential 2020 Lancet Commission on Dementia Prevention, which adjusted for overlapping risk factors such as hypertension and diabetes.² The authors of the present study contend that such adjustments may underestimate the true contribution of hearing loss, especially when risk factors work together through similar biological or behavioral pathways, such as sensory deprivation, social isolation, or increased cognitive load.

PAF estimates were generally higher among women, White participants, and those over age 75, largely reflecting differences in hearing loss prevalence across these groups. However, the authors caution that small sample sizes, especially among Black participants, limited the precision of their estimates.

In comments to HearingTracker, study co-author Jason Smith, PhD, a researcher in the Department of Epidemiology at Johns Hopkins Bloomberg School of Public Health, underscored the population-level aspect of the research. “We acknowledge that we still don’t know with certainty whether treating hearing loss reduces an individual’s risk of dementia,” he said. “However, this provides strong evidence, within the same sample that demonstrated benefit in ACHIEVE, that a large fraction of population-level dementia risk could be associated with hearing loss. The fact that up to 32% of population-level dementia risk could potentially be delayed or prevented from treating hearing loss in older adults signals a major prevention gap.

“The public health implications that addressing an important modifiable risk factor—even in later life—could delay a large fraction of dementia risk at the population level are encouraging,” added Smith. “Yet more research is needed to investigate whether treating hearing loss at the individual level can reduce dementia risk.”

In the future, Smith says the research group plans to investigate the population-level risk of multisensory deficits, such as combined hearing and vision loss, on brain health.

Beyond differences in population-level impact, the study provides a critical comparison between subjective and objective hearing measures. While self-reporting is easier to collect on a large scale, the authors say it may be better at capturing the perceived impact of hearing loss rather than true auditory function. This is a distinction that matters: in the current analysis, self-reported hearing loss was not associated with an increased risk of dementia at all. The implication is that studies relying on self-report may be missing important links between hearing and cognitive health, particularly in the older adults most at risk for both (e.g., the ARIC population).

Although hearing aid use was associated with a modest reduction in dementia risk, the results were not statistically robust enough to draw firm conclusions. This may be due to insufficient follow-up time or a lack of data on how consistently participants used their devices. However, the authors point to a meta-analysis study in which hearing aid users had a 29% lower risk of cognitive decline compared to non-users, offering indicating that treating hearing loss may provide cognitive benefits over time.³

The researchers emphasize that, unlike many other dementia risk factors, hearing loss is both common in late life and treatable. With access to technologies like hearing aids and cochlear implants—and greater awareness of environmental risk factors such as noise exposure and ototoxic medications—there may be real potential for public health strategies aimed at preserving hearing to help reduce dementia rates.

There are some limits to the study, including the lack of more racial or ethnic groups, dementia diagnosis based on hospital and death records, and survivor bias, where individuals with early hearing loss who developed dementia might not have returned for later follow-up assessments. Additionally, data on hearing aid usage did not include information about device quality, fit, or daily use—factors known to influence outcomes.

Hearing loss gains status as a critical public health issue

Despite these caveats, the findings add to a growing body of literature⁴ suggesting that hearing loss is not just a benign aspect of aging; particularly for those who are at risk, it could be a key lever relative to dementia. Importantly, the authors call for future studies to prioritize objective hearing testing and to focus on populations most likely to underreport hearing difficulties, including the oldest adults.

The worldwide population of people living with dementia is expected to triple in the coming decades. As the healthcare community continues to grapple with how best to delay or prevent dementia, this study suggests that hearing care may have a more central role than previously recognized. While questions remain about the exact mechanisms and the long-term effects of hearing interventions, the takeaway is clear: hearing loss should not be overlooked in the broader conversation about cognitive health in aging populations.