Hearing loss and dementia: what the latest evidence shows

What we mean by hearing loss and dementia

Age-related hearing loss (presbycusis) usually develops gradually from the mid-50s onwards. It typically affects both ears and makes higher-pitched sounds — including consonants like "s", "t" and "f" — harder to pick up. People often notice it first in background noise: restaurants, family gatherings or group meetings.

Dementia is an umbrella term for a decline in memory, thinking and everyday function. Alzheimer's disease is the most common form, but there are others, including vascular dementia. In the UK, around one in eleven people over 65 lives with some form of dementia.

Is there really a link between hearing loss and dementia?

Yes — and it is now one of the most consistent findings in dementia research.

The Lancet Commission on dementia prevention (2020, updated 2024) reviewed the evidence on modifiable risk factors across the life course. Hearing loss in mid-life came out as the single largest of these factors. The Commission estimates that addressing hearing loss could prevent or delay around 7% of dementia cases worldwide — more than any other single factor they examined.

The connection has been shown across large population studies in the UK, the US, Europe and Asia. Broadly, the greater the untreated hearing loss, the higher the long-term risk of cognitive decline.

Why might untreated hearing loss raise the risk?

Researchers don't yet have a single definitive answer, but several plausible mechanisms are being studied together:

• Increased cognitive load. When speech isn't clear, the brain has to work harder to fill in the gaps. Over years, that extra effort may divert resources away from memory and other cognitive functions.
• Social withdrawal and low mood. People who struggle to follow conversations often start avoiding them. Loneliness and depression are independently linked to cognitive decline.
• Changes in brain structure. Imaging studies suggest that long-standing hearing loss is associated with faster shrinkage in areas of the brain that process sound and language.

The relationship also appears to hold for vascular dementia, not just Alzheimer's disease — reinforcing the idea that the effect is at least partly driven by the consequences of poor hearing, rather than a single disease process.

Do hearing aids reduce the risk?

This is the question patients ask me most often, and until recently the honest answer was "probably, but we don't have proof". The picture has now shifted.

The ACHIEVE trial (published in The Lancet, 2023) was the first large, randomised study to look at whether treating hearing loss slows cognitive decline. Almost 1,000 older adults with untreated hearing loss were randomised either to a hearing intervention (professionally fitted hearing aids plus audiological counselling) or to a health-education control group, and followed for three years.

Among participants who were already at higher risk of cognitive decline, those who received hearing aids showed roughly 48% less cognitive change over three years compared with the control group. In the healthier subgroup the benefit was smaller, but the overall signal — especially for people most at risk — was clear and clinically meaningful.

ACHIEVE doesn't prove that hearing aids prevent dementia, and more research is under way. But combined with the wider evidence base, it strongly supports treating hearing loss early rather than waiting.

What about the NHS view?

NHS guidance and public health bodies in the UK now recognise hearing loss as a modifiable risk factor for dementia and recommend that adults have their hearing checked if they, or those around them, notice a change. The message from audiology, neurology and public health is broadly aligned: don't leave hearing loss untreated.

Signs it's worth acting on now

You don't need to wait for a formal diagnosis to have your hearing assessed. Common early signs include:

• Struggling to follow conversation in restaurants, cafés or group settings.
• Turning the television up louder than others in the room find comfortable.
• Frequently asking people to repeat themselves, especially on the phone.
• Feeling unusually tired after social events or long meetings.
• Family members mentioning your hearing before you do.

Any one of these on its own is not proof of hearing loss — but together they are a reasonable prompt for a proper assessment.

What a hearing assessment involves

A full private hearing assessment at Drummond Hearing takes around an hour. It includes a careful history, otoscopy (a look inside the ear), diagnostic pure-tone audiometry across the frequencies used for speech, and speech testing where appropriate. You leave with a clear explanation of your results and, if any treatment is needed, independent advice about the options — from a simple wait-and-review plan through to modern AI-enabled hearing aids from Starkey, Phonak or GN ReSound.

Acting early tends to make the whole process easier. Modern hearing aids are small, discreet and, when fitted well, genuinely comfortable — and the sooner the brain is receiving a clearer signal, the better.

Related reading: What is earwax? Why we have it, and when it needs removing.