Most research today agrees that untreated hearing loss is strongly tied to a higher risk of dementia, although hearing loss does not automatically cause dementia and not everyone with hearing loss will develop it.
Scientists have been studying this link for more than a decade. Large population studies, including work cited by the Lancet Commission on Dementia, have found that older adults with hearing loss have a significantly higher chance of developing dementia compared with those who hear normally, even after accounting for age, education, and other health problems.[4] One recent analysis reported that hearing loss was associated with roughly a 30 to 50 percent increase in dementia risk and may account for around 7 percent of dementia cases worldwide.[4] Clinical resources such as Bravo Hearing Center also describe how people with untreated hearing loss are more likely to experience cognitive decline than those who use hearing support like hearing aids.[1] You can read more about that relationship at https://www.bravohearing.com/hearing-loss-and-dementia/.
Specialists now often say that hearing loss is not just an ear problem, it is a brain problem. The ears pick up sound, but the brain does the heavy work of making sense of speech and noise. When hearing is reduced, the brain receives a muffled, incomplete signal and must work harder to fill in the gaps. Researchers call this extra effort “increased cognitive load.”[4][6] Because so much mental energy is spent just trying to decode speech, there are fewer resources left for memory, thinking, and planning. Over time, this constant strain may wear down the brain’s ability to cope with other changes that come with aging, which can increase vulnerability to dementia.[4]
Another key idea is “sensory deprivation.” When hearing loss is untreated, the brain’s sound processing centers receive less input. Brain imaging studies suggest that when certain areas are underused for a long time, they can shrink or change in structure.[4] The regions that handle sound are closely connected to those involved in memory, language, and attention. If sound pathways weaken, nearby networks may also be affected. Articles written for patients, such as those from Alabama ENT Specialists and other hearing clinics, explain that reduced auditory stimulation can gradually weaken parts of the brain that support memory and comprehension.[3][5][7] Alabama ENT discusses this process at https://www.alabamaentspecialists.com/how-untreated-hearing-loss-affects-balance-memory-and-safety/.
Social connection is another important piece. Hearing loss often makes conversations difficult, especially in noisy places like restaurants or family gatherings. Many people begin to avoid social situations because they feel embarrassed, exhausted, or left out. This can lead to isolation and loneliness, which are themselves known risk factors for cognitive decline and dementia.[4] Clinical articles emphasize that untreated hearing loss can cause people to withdraw from stimulating activities, reducing mental engagement and speeding up decline in thinking skills.[1][3][5][7] When you remove everyday conversations, jokes, group discussions, and phone calls, the brain loses a major source of exercise.
Newer studies are also starting to look at younger and middle aged adults. Research summarized in medical databases like PubMed notes that individuals with untreated hearing loss at these ages can also experience cognitive problems related to increased cognitive load and reduced sensory stimulation.[6] This suggests that hearing health matters long before traditional “old age.” You can see an example abstract explaining this mechanism at https://pubmed.ncbi.nlm.nih.gov/41440509/.
Importantly, hearing loss itself is considered a “modifiable” risk factor. That means it is something that can be addressed, unlike age or genetics. The Lancet Commission lists hearing loss as one of the top midlife factors that can be changed to help reduce the overall burden of dementia.[4] Audiologists and medical authors often describe it as part of a “domino effect”: hearing loss makes listening harder, which leads to strain and withdrawal, which then undermines cognitive health over time.[5] Hear Carolina, for instance, writes about how untreated hearing loss can contribute to cognitive decline and how early care may help protect brain health, at https://www.hearcarolina.com/blog/hearing-loss-and-dementia-cognitive-decline-prevention/.
One of the most hopeful parts of this story is that treating hearing loss may lower dementia risk. A number of observational studies have compared people with hearing loss who use hearing aids to those who do not. An educational breakdown by an audiologist on YouTube summarizes recent research suggesting that people with untreated hearing loss had significantly higher dementia risk, while those who wore hearing aids did not show a meaningful increase in risk compared with people without hearing loss, although these results come from non randomized studies.[2] That video, “New Research: Hearing Loss & Dementia,” can be found at https://www.youtube.com/watch?v=Q1X2pQDSTto. Clinic sites like Rocky Mountain Audiology and Bravo Hearing also describe how hearing aids and other interventions can support brain function by restoring access to sound, making communication easier, and encouraging ongoing social engagement.[1][5][7] Rocky Mountain Audiology discusses this topic at https://www.rockymountainaudiology.com/hearing/hearing-loss-and-dementia.php.
It is important to be clear that “linked to” or “associated with” is not the same as “always causes.” Dementia has many contributing factors, including genetics, blood vessel health, diabetes, smoking, head injury, education, and more.[4] Some people with excellent hearing still develop dementia, and many with long standing hearing loss never do. However, the consistent pattern across many studies is that, at a population level, average risk is higher when hearing loss is present and not managed. The exact size of the risk varies by study, but the direction of the effect is quite consistent.[4]
For everyday life, the message is practical. If someone is turning up the television, asking others to repeat themselves, feeling that people mumble, or avoiding noisy social settings, it is worth taking these signs seriously. Getting a professional hearing test provides a clear picture of current hearing levels. If hearing loss is found, options such as hearing
