Hearing aids may slow onset of dementia and Alzheimer's. Here's why.

As we age, connections between cells in the brain are damaged, or some cells are lost—a process that has scarily been called “brain atrophy” or simply “cognitive decline," which can eventually lead to dementia.

The reasons this happens are complex, of course. Some causes of cognitive decline are inevitable (such as genetics), but other causes are controllable. The good news: Hearing loss appears to fall into the latter category.

This means that when you take steps to prevent or treat hearing loss, you are helping reduce your risk of dementia, noted a landmark report from the British medical journal Lancet. Other risk factors you can modify include high blood pressure, high alcohol intake, smoking, depression, social isolation, and physical inactivity, among others.

The big question you may be asking: If I have hearing loss, will hearing aids or cochlear implants help prevent dementia? Let's take a look at what the research says.

Do hearing aids prevent cognitive decline?

First, a long-awaited 2023 randomized controlled trial provides important new clarity on this question. The study investigated the impact of hearing loss intervention on dementia. The intervention included use of hearing aids, a hearing “toolkit” to assist with self-management, and ongoing instruction and counseling with an audiologist.

The results showed that over a three-year span, the intervention reduced the typical rate of expected cognitive decline among adults aged 70–84. However, the benefit was limited to people who had not just hearing loss but also other risk factors for dementia, such as heart disease, lower educational levels and limited physical activity.

'There's really no downside to it'

Still, "the clinical takeaway is that almost anyone with hearing loss as an older adult should get their hearing checked and address hearing issues if there are any. There's really no downside to it. Hearing intervention comes at no risk," stated Dr. Frank Lin, lead author of the study and director of the Cochlear Center for Hearing and Public Health at Johns Hopkins University, in an interview on the study.

Prior to that study, a 2022 meta-analysis of 31 studies found hearing aids and cochlear implants are linked with a lower risk of cognitive decline. The study was published in the Journal of the American Medical Association-Neurology.

Separately, a very large observational study found that hearing aids appeared to delay the onset of cognitive impairment and dementia, along with depression, social isolation and falls that cause injuries. However, it was not a randomized controlled trial, so the results could have been for other reasons (for example, hearing aid wearers have higher incomes and thus more access to good medical care).

As well, one large 2018 study analyzed results from more than 2,000 Americans age 50 and up who took word recall tests every two years for up to 18 years. Among those who acquired hearing aids along the way, the evidence suggested that the aids slowed the rate they lost memory of words.

More: Health benefits of hearing aids.

What are the best hearing aids for dementia?

For people with hearing loss and diagnosed dementia, hearing loss should never be ignored, as it may exacerbate dementia symptoms, increase their disorientation and make their environment less safe (they can't hear a running faucet, for example). 

While there are no hearing products made specifically for dementia patients, there are plenty of hearing aid types and styles out there that can still be helpful.

Here at Healthy Hearing, we frequently hear from the children and caretaker of adults with dementia who are thrilled with how hearing aids improved their loved one's life. You can see real-life examples in this article: You're never too old for hearing aids.

Hearing loss makes living with diseases like Alzheimer's even more challenging. For people currently affected by dementia, hearing aids or other hearing devices are recommended to improve their quality of life and make communication easier.  

If you are the caretaker of someone with Alzheimer's or a similar disease that affects cognition, you are wise to investigate what hearing devices might work best. A hearing care provider will be your ally in this journey, as they'll know the latest products that may work for your loved one. You'll also be able to discuss your loved one's specific needs, habits and abilities with the hearing care specialist.

Keep in mind hearing aids may not always be the best solution. Most premium hearing aids are designed to be discreet, so they may be too small and too easy to lose for a patient with dementia, especially if they have dexterity problems. Hearing aids also require that a person (or their caretaker) remember to keep the batteries charged and the device clean and in good working condition. In some cases, assistive listening devices may work better. 

Is there a link between hearing loss and dementia?

Many studies have found an association between untreated hearing loss, Alzheimer's disease and other types of dementia. Meaning, people with hearing loss are more likely to develop cognitive problems than people who do not have hearing loss.

A study published in July 2021 found that people who struggle to hear speech in noise were more likely to develop dementia than those with normal hearing, as measured over an 11-year period. This was the first time that speech in noise was specifically studied. However, the study wasn't capable of determining if untreated hearing loss caused the dementia, only that they're linked. 

In a different study, a team at Johns Hopkins looked at cognitive impairment scores over six years for nearly 2,000 seniors. They concluded that those with hearing loss had a faster decline. The volunteers were all cognitively normal when the research began. But by the study’s end, people with hearing loss were 24 percent more likely to meet the standard of cognitive “impairment” compared to people with normal hearing. 

Even moderate hearing loss is a risk factor

Another approach is to ask people whether they’ve noticed a change. Measures of “subjective” decline can pick up losses before they’ll show up on a test. A large study—using data drawn from more than 10,000 men age 62 and up—ran over eight years. It found that the greater their hearing loss, the more likely men were to express concerns about their memory or thinking over time. With even moderate hearing loss, their chance of reporting cognitive decline was 30 percent higher than among those who did not report any hearing loss. With moderate or severe hearing loss, the risk was 42 and 52 percent higher. (At age 80 or above, moderate hearing loss is more common than mild hearing loss.)

Dr. Sharon Curhan, a doctor and epidemiologist at Brigham and Women’s Hospital in Boston, who led this study, said she plans further research with women and younger populations.

Lastly, a Salt Lake City team found that among nearly 4,500 seniors without dementia, 16.3 percent of those with hearing loss developed dementia compared to 12.1 percent of those with normal hearing. It also tended to occur faster in people with hearing loss. On average, it took a bit over a decade to develop dementia among the group with hearing loss, and 12 years if your hearing was fine.

More: Slight hearing loss linked to cognitive decline in new study

Hearing loss can mimic cognitive decline and Alzheimer's

Don’t assume you’re suffering from dementia if you’re having trouble understanding speech, or finding it exhausting to have simple conversations. Hearing loss has some of the same symptoms as cognitive impairment, so it’s vital to have regular hearing checks.

More: 'I thought I had cognitive decline, but it was hearing loss'

What about tinnitus and Alzheimer's?

Alzheimer's disease is slightly more common among people who have tinnitus than people who don't, at least one study has indicated. In that study, conducted in Taiwan, 3.1% of tinnitus patients developed Alzheimer's over a 10-year period, compared to 2% of those who did not have tinnitus. However, scientists do not know why this relationship exists, and more research is needed. 

If you need help with hearing loss

If you're noticing trouble hearing in yourself or a loved one, don't delay—prompt treatment with hearing aids or cochlear implants can help you or your loved one stay engaged in the world and avoid social isolation, a common problem for people with untreated hearing loss.

Hearing loss is exhausting, but it doesn't have to be. To find a hearing care professional, see our directory of consumer-reviewed hearing clinics to find a hearing specialist or audiologist near you.

More: Clinical trials on hearing loss - how to participate