Do hearing aids protect memory? What the ACHIEVE trial found, and what it changed for us
After the sudden hearing loss scare, Dad had a full hearing test and walked out with a recommendation for hearing aids in both ears. He wore them for about a week and then they lived in a drawer. Too fussy, too loud, made him feel old.
I tried a new argument. I'd read headlines saying hearing aids could help prevent dementia, and my grandmother had dementia, so I figured that would get his attention. It did, but when I went looking for the actual research to show him, the story turned out to be more complicated than the headlines. What follows is what I found, and why I ended up making a different argument.
Why researchers think there's a link
The National Institute on Aging says studies have shown older adults with hearing loss have a greater risk of developing dementia than people with normal hearing. In 2024 the Lancet's standing commission on dementia, a large international panel, published an updated report on dementia prevention listing 14 risk factors that can be changed, hearing loss among them. Together they estimated that nearly half of dementia cases might in theory be prevented or delayed by addressing all 14.
Nobody is sure why hearing loss is linked to dementia. Ideas include the extra mental effort of straining to hear, which may take resources away from memory, the social isolation that comes when conversation gets hard, and possibly shared causes in the aging brain. A link, though, isn't the same as proof that treating hearing loss protects memory. That's what ACHIEVE set out to test.
The ACHIEVE trial
ACHIEVE was a randomized trial run at four sites across the US and funded by the National Institutes of Health. It's registered on ClinicalTrials.gov and the main results were published in The Lancet in 2023.
- 977
- adults aged 70 to 84 with untreated hearing loss and no substantial memory problems
- 3 years
- of follow-up, with checkups every six months
- 2 groups
- hearing care with hearing aids, or health education sessions
Source: Lin and colleagues, The Lancet, 2023.
| Hearing intervention group | Comparison group | |
|---|---|---|
| What they got | Sessions with an audiologist, hearing aids, counseling on using them | Sessions with a health educator on preventing chronic disease |
| Number of people | 490 | 487 |
| Main measure | Change in a combined score of thinking and memory tests over 3 years | Same |
The participants came from two places. About a quarter were from a long-running heart study called ARIC. They were older, had more risk factors for cognitive decline and started with lower test scores. The other three quarters were healthy volunteers recruited fresh from the community.
The main result
Over three years, both groups' thinking scores declined, which is normal at that age. And they declined by almost exactly the same amount.
Change in a combined cognition score, in standard deviation units. A bigger bar means more decline.
| Group | Decline over 3 years |
|---|---|
| Hearing intervention (490 people) | 0.200 |
| Health education (487 people) | 0.202 |
Source: Lin and colleagues, ACHIEVE trial, The Lancet, 2023.
In the whole group, hearing aids made no measurable difference to cognitive decline over three years. That was the primary result, and the authors reported it plainly.
The part the headlines picked up
The researchers had planned in advance to check whether the effect differed between the two populations. It did. The difference between the higher-risk ARIC participants and the healthy volunteers was statistically significant. The authors' interpretation was that a hearing intervention might reduce cognitive change over three years in older adults at higher risk of cognitive decline, but not in those at lower risk.
That's interesting and worth following. It's also a secondary analysis, in a subgroup of about 240 people, over three years. Put simply, hearing aids didn't slow decline in healthy older adults in this trial, and might help people who are already at higher risk. More follow-up will tell.
What the observational studies add
ACHIEVE is the strongest kind of evidence, a randomized trial, but it isn't the only evidence. The NIA's page also mentions a recent analysis that pooled several studies and found that people who used hearing aids or cochlear implants had a lower risk of long-term cognitive decline than people whose hearing loss went untreated.
That kind of study follows people who chose hearing aids on their own, so it can't fully separate the hearing aids from everything else about people who wear them. They may be healthier, wealthier or more social to begin with. Put next to ACHIEVE, my reading is that the link is real, the protective effect is possible but unproven for healthy people, and the clearest benefit is the everyday one: hearing the people around you.
The argument I made instead
I'm glad I read the actual paper before I told my father that hearing aids would protect him from my grandmother's fate. That's not what the evidence says, and he'd have caught me overselling it. He was a surveyor. He checks measurements.
So I made a different argument, one the trial couldn't argue with. Hearing aids won't promise anything about dementia. What they do is let him follow the conversation at his Thursday coffee group, hear his granddaughter on the phone, and stop coming home from dinners exhausted. The NIA notes that hearing loss can push people toward isolation, and isolation was the thing I could actually see happening to him.
He went back to the audiologist for a refit. They turned the volume down at first and built it up over a few weeks, which helped a lot. He wears them most days now, and he's back at the coffee group.
Questions we brought to the refit
Dad's first fitting went badly partly because nobody asked him what bothered him. The second time we went with a list:
- Can you start the volume lower and raise it over a few weeks?
- Which of his complaints are about the fit, and which are about getting used to sound again?
- Is there a simpler setting with fewer programs for a man who doesn't want to fiddle?
- How should he clean them, and how often should he come back?
- Is there a trial period if they still don't work for him?
The audiologist had answers for all five, and the third one mattered most. One program, one button, no app. He's worn them nearly every day since.
If your parent is in the same spot
- Get a full hearing test first. Knowing what to expect at a hearing test makes the appointment less intimidating; this guide on what to expect at a hearing test covers it.
- Talk about the life they're missing, not about dementia.
- Go to the fitting with them, and to at least one follow-up.
- Expect a few weeks of adjustment. Most of the "too loud, too tinny" complaints fade as the brain gets used to sound again.
- Keep reading from careful sources. I've found these plain-English hearing guides more measured than most of what comes up in a search.
And keep the bigger picture in mind. Hearing aids are one piece. Exercise, blood pressure, staying social and staying curious all matter too, and those are things families can help with every week.