Hearing Aids and Dementia: What Does the Research Really Show?
Hearing loss affects far more than the ability to follow a conversation. Researchers are increasingly studying its relationship with cognitive health, including whether untreated hearing loss may be associated with a greater risk of cognitive decline and dementia.
This has led to a growing question among patients and families: Can wearing hearing aids help protect the brain?
The research is encouraging in some respects, but the answer is more nuanced than many headlines suggest. Hearing loss has been consistently associated with dementia risk, and some studies suggest that treating hearing loss may be beneficial for certain people. However, researchers have not established that hearing aids prevent dementia.
Understanding the difference between an association and a proven preventive effect is important when interpreting the research.
Hearing Loss Is Considered a Modifiable Dementia Risk Factor
The 2024 report from the Lancet Standing Commission on dementia prevention, intervention, and care identified 14 potentially modifiable risk factors associated with dementia.
Hearing loss was one of the most significant factors identified. The Commission estimated a population attributable fraction of approximately 7% for hearing loss.
That number requires some context.
A population attributable fraction is a statistical estimate of how much disease might theoretically be avoided at the population level if a particular risk factor could be eliminated, assuming that the relationship is causal.
It does not mean that treating hearing loss will prevent 7% of dementia cases. Researchers are still working to determine exactly how hearing loss and dementia are connected.
Why Might Hearing Loss Be Connected to Cognitive Health?
Researchers have proposed several possible explanations.
Increased listening effort
When hearing becomes more difficult, the brain may need to devote additional resources to understanding speech and interpreting incomplete auditory information.
That increased listening effort could leave fewer cognitive resources available for other tasks such as memory and comprehension.
Reduced social interaction
Hearing loss can also make conversations frustrating or exhausting. Some people gradually participate less in social activities because following conversations becomes difficult.
Social isolation itself has been associated with poorer cognitive outcomes, making social engagement one possible link between hearing and brain health.
Changes involving the brain
Research using brain imaging has also identified differences in brain structure and function among some people with hearing loss.
Scientists are still determining whether those changes contribute to cognitive decline, result from other aging processes, or reflect a combination of factors.
These explanations remain hypotheses. None has yet been established as the single mechanism connecting hearing loss and dementia.
What Did the ACHIEVE Trial Find?
One of the most important studies examining this question is the Aging and Cognitive Health Evaluation in Elders, or ACHIEVE, randomized clinical trial.
Published in The Lancet in 2023, the study included 977 adults between ages 70 and 84 who had untreated hearing loss but did not have substantial cognitive impairment.
Participants received either a comprehensive hearing intervention that included hearing aids and audiological counseling or a health-education intervention.
After three years, researchers found no statistically significant difference in cognitive decline between the two groups when all participants were analyzed together.
That finding is important because randomized controlled trials can provide stronger evidence about cause and effect than observational studies.
However, researchers also found an intriguing difference within one of the study populations.
Participants who came from the Atherosclerosis Risk in Communities study were generally older and had more risk factors for cognitive decline. Among these higher-risk participants, the hearing intervention was associated with substantially slower cognitive decline.
The researchers reported approximately a 48% reduction in the rate of cognitive decline in this group compared with the health-education control group.
The finding does not establish that hearing aids protect everyone from dementia. It does suggest that hearing intervention could have greater cognitive benefits for certain older adults who already have an elevated risk of cognitive decline.
Newer Research Suggests Effective Hearing Treatment May Matter
Research published since the ACHIEVE trial has added another piece to the puzzle.
A 2026 study published in Cell Reports Medicine analyzed longitudinal data from 61,089 adults with hearing impairment across 33 countries.
Over an average follow-up of approximately 6.5 years, hearing aid use was associated with about a 9% lower risk of probable dementia compared with untreated hearing loss.
More interestingly, the association appeared to depend on how well the hearing aids actually improved hearing.
Participants who reported effective hearing improvement with their hearing aids had a lower risk of probable dementia. Those who reported poor improvement did not have a statistically significant reduction in risk compared with people who were not using hearing aids.
Because this was an observational study, it cannot prove that the hearing aids themselves caused the difference. However, the findings suggest that simply owning hearing aids may not be enough. Appropriate fitting, regular use, follow-up care, and meaningful improvement in hearing may all matter.
Could Starting Hearing Aids Earlier Make a Difference?
Another study suggests that timing may also deserve further attention.
Researchers analyzing nearly 3,000 participants from the Framingham Heart Study reported their findings in JAMA Neurology in 2025.
Among participants younger than 70 when their hearing was assessed, hearing aid users with hearing loss had a significantly lower incidence of dementia during follow-up compared with participants who had hearing loss but did not use hearing aids.
The same association was not statistically significant among participants who were 70 or older.
Again, this was an observational study, so it cannot show that starting hearing aids earlier prevents dementia. People who seek hearing care may differ from nonusers in access to health care, socioeconomic factors, general health behavior, and other characteristics.
Still, the study raises an important question for future research: Could addressing hearing loss earlier in life be more beneficial than waiting until hearing difficulties become severe?
Why Researchers Are Still Cautious
Despite increasingly strong evidence connecting hearing loss and cognitive health, scientists have several reasons to avoid describing the relationship as proven cause and effect.
Hearing loss and cognitive decline share many potential contributing factors, including age and vascular disease.
Another possibility is reverse causation. Changes associated with the early stages of dementia can begin many years before a diagnosis and may affect the brain’s ability to process sound. In some cases, hearing difficulties could therefore be an early consequence or marker of neurological change rather than a cause of dementia.
Researchers must also account for differences between people who seek hearing treatment and those who do not.
A 2026 review in the Journal of Alzheimer’s Disease highlighted several factors that can complicate hearing-and-dementia studies, including measurement error, shared biological causes, reverse causation, and selection bias.
For these reasons, researchers continue to emphasize the distinction between association and causation.
So, Can Hearing Aids Prevent Dementia?
Based on the evidence available today, it would be premature to say that hearing aids prevent dementia.
A more accurate conclusion is this:
Untreated hearing loss is consistently associated with a greater risk of cognitive decline and dementia, and emerging evidence suggests that effective hearing treatment may offer cognitive benefits for some people, particularly those at greater risk or those who address hearing loss earlier.
More research is needed to determine how much of the relationship is causal and which patients may receive the greatest cognitive benefit from hearing intervention.
What is already well established is that appropriately fitted hearing aids can improve access to sound and communication for people with hearing loss. Better hearing can make conversations easier, support social participation, and improve day-to-day communication.
Those benefits are valuable regardless of whether hearing treatment ultimately proves to have a direct role in dementia prevention.
For adults noticing changes in hearing, a comprehensive hearing evaluation can help determine the degree and type of hearing loss and whether hearing technology or another form of treatment may be appropriate.
References
- Livingston G, Huntley J, Liu KY, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet. 2024;404(10452):572-628. doi:10.1016/S0140-6736(24)01296-0.
- Lin FR, Pike JR, Albert MS, et al. Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial. The Lancet. 2023;402(10404):786-797. doi:10.1016/S0140-6736(23)01406-X.
- Jiang F, Dong Q, Jayakody DMP, et al. Hearing aid effectiveness and probable dementia risk across 33 countries: A pooled analysis of seven cohorts. Cell Reports Medicine. 2026;7(5):102802. doi:10.1016/j.xcrm.2026.102802.
- Francis L, Seshadri S, Dillard LK, et al. Self-Reported Hearing Aid Use and Risk of Incident Dementia. JAMA Neurology. 2025;82(11):1195-1197. doi:10.1001/jamaneurol.2025.2713.
- Merten N, Dawes P, Munro KJ, Brenowitz WD. Hearing impairment and cognitive decline: Alternative explanations to causality. Journal of Alzheimer’s Disease. 2026;110(1 suppl). doi:10.1177/13872877251410502.
- Science Blog Editorial Team. Hearing Aids and Dementia: What the Evidence Actually Shows. ScienceBlog. Published August 2, 2026; updated September 11, 2026.
