Hearing Aids and Dementia Risk: What the Evidence Says

What observational studies show

Many studies that follow older adults over years have found that those with hearing loss are more likely to develop cognitive decline and dementia than those with normal hearing. One widely cited American study reported that the risk increased with the degree of loss, being roughly two, three and five times higher for mild, moderate and severe hearing loss, respectively, compared with normal hearing. Later studies in different countries have found similar associations, though the size varies. The Lancet Commission on dementia prevention, intervention and care has listed hearing loss as one of the largest potentially modifiable risk factors for dementia, estimating that it may account for several per cent of dementia cases at the population level if the link is causal.

Important caution: these studies show association, not proof of cause. People with hearing loss may differ from others in many ways, and early dementia may itself affect hearing tests and listening. So the link may be partly due to other shared causes, partly to reverse causation, and partly to a genuine effect of hearing loss on the brain. See also understand the connection between hearing loss and dementia and why do hearing loss and dementia go hand in hand.

Why hearing and thinking may be linked

Researchers have proposed several, non-exclusive explanations:

• Cognitive load. When hearing is poor, the brain spends extra effort decoding sound, leaving fewer resources for memory and thinking.
• Brain changes. Reduced input from the ears may lead to changes in the brain's auditory areas and wider networks, and possibly to faster shrinkage of some regions.
• Social isolation and depression. Hearing loss makes conversation hard, so people withdraw. Loneliness and low mood are themselves risk factors for cognitive decline; see hearing loss and isolation in later life.
• Reduced activity and stimulation.
• Common causes. Blood vessel disease, diabetes, high blood pressure and other conditions can damage both the ear and the brain.
• Testing effects. Memory tests that rely on hearing can make a person with hearing loss appear worse than they are.

What the clinical trial found

For years the key question was: if you treat hearing loss, does it reduce cognitive decline? Small and observational studies suggested that hearing aid users had slower decline, but these could be biased, since people who get aids may be healthier and more engaged. A large randomised trial in the United States, known as ACHIEVE, tested a hearing intervention (hearing aids, counselling and education) against a health education programme in adults aged about seventy to eighty-four with untreated hearing loss and no dementia, over about three years. It was reported in 2023.

• Overall, there was no significant difference in cognitive decline between the groups in the whole study population over three years.
• In a pre-planned subgroup at higher risk of decline (older adults from a community-based study with more risk factors), the hearing intervention appeared to slow cognitive decline substantially, by around half, compared with the control group.
• Participants in the hearing group reported better communication and other benefits.

So the evidence is encouraging but not definitive. It suggests that treating hearing loss may help protect thinking in some people, particularly those at higher risk, though the trial was not long enough to show the effect on diagnosed dementia. More research, longer follow-up and other populations are needed, including studies in India and other countries with different health systems. Not every researcher agrees on how to interpret the results.

What this means in practice

• Hearing aids are not a proven way to prevent dementia, and families should not promise it. They are a proven way to help people hear, communicate and take part, and they may protect brain health in some people.
• Untreated hearing loss is worth treating on its own merits: better understanding, safer living, less isolation, more independence and better mood.
• The benefit depends on use. Aids in a drawer do nothing; see the first weeks with a hearing aid: what to expect.
• Other risk factors matter too: blood pressure, diabetes, smoking, physical inactivity, depression, vision loss, social isolation, alcohol, head injury and air pollution are all linked to dementia risk in the Lancet Commission's analyses. Vision loss is on the list too; see a hearing and vision check-up schedule after 60.
• Do not blame the person. Hearing loss is common and not a failure.

When memory seems poor: check hearing and vision first

If a parent seems forgetful or confused, do not assume dementia without checking the basics:

1. Hearing test and hearing aids, with wax removal if needed; see a hearing test: what to expect and ear wax and hearing: safe care. 2. Eye examination and correct glasses; see reading glasses, bifocals and varifocals: falls and choices. 3. Medicines review, since some can cause confusion; see medicine side effects families should watch for and polypharmacy and deprescribing. Never stop medicines without the doctor. 4. Other treatable causes: infection, low sodium, thyroid, vitamin B12 deficiency, depression, sleep apnoea and dehydration; see delirium in older adults. 5. Cognitive assessment done fairly: with aids and glasses in, in a quiet room, with clear speech and written support.

A sudden change in thinking, confusion or behaviour over hours or days is an emergency (possible delirium or stroke): call a doctor at once, or 112 if with weakness, facial droop or speech difficulty.

See mild cognitive impairment: what it is and what families can do and caring for a parent with dementia at home.

If your parent already has dementia

Hearing aids and glasses still matter. Sensory loss can worsen confusion, agitation and withdrawal. But use needs adaptation:

• Choose simple aids with few controls, rechargeable or easy batteries, and a caregiver to insert, check and clean them daily; see hearing aid care, batteries and troubleshooting.
• Introduce gradually, with patience and praise, and check comfort. Some people reject aids; try again later or try a different device, such as a personal amplifier with a headset for conversation, under audiology guidance; see hearing aid or personal sound amplifier: what is the difference?.
• Label the aids and keep them safe; batteries are dangerous if swallowed.
• Use communication strategies; see communicating with someone who has dementia and talking with someone who is hard of hearing.
• Check ears regularly for wax and discomfort, since the person may not report it.
• Tell professionals about the hearing loss, so that tests and care are adapted.

What families can do now

1. Arrange a hearing test for any parent over sixty who may be struggling, and repeat it at the recommended intervals; see signs of hearing loss in parents and how to raise it gently. 2. Treat what can be treated: wax, infections, hearing aids and devices; see hearing aids: types, costs and how to choose. 3. Support use, with follow-up visits and encouragement. 4. Keep the brain and body active: conversation, reading, hobbies, learning, music, exercise, social contact and good sleep; see walking programme for older adults. 5. Manage blood pressure, diabetes and cholesterol, stop smoking and limit alcohol. 6. Protect hearing from noise. 7. Check vision too. 8. Watch mood, and seek help for depression and anxiety. 9. Stay realistic: hearing aids help people hear; any brain protection is an added possibility, not a promise.

Avoiding false claims

Be wary of advertisements that claim a hearing aid or a supplement will prevent or reverse memory loss. No such product has been proven to do so. Research is ongoing. If you see such claims, ask an audiologist or doctor.

When to ask a professional

Ask an audiologist for a hearing test and advice on aids and communication. Ask a doctor for a memory assessment if there are concerns, and request that it takes account of hearing and vision. Ask an ophthalmologist or optometrist for an eye check. Seek urgent care for sudden hearing loss, sudden confusion or any stroke signs; call 112 for weakness, facial droop, speech difficulty or severe dizziness.