Hearing loss and dementia are two conditions that become more common as we get older. They can make it harder to communicate, stay connected with other people and take part in everyday life.
This World Alzheimer’s Day, we’re exploring what hearing loss and dementia mean for people living with both conditions, and how RNID-funded research is helping us better understand their connection.
Learn what we know about the association between hearing loss and dementia.
David’s story
David is a 74 year-old retiree from Nottinghamshire, who has been diagnosed with mixed dementia (Alzheimer’s and vascular dementia). David’s journey with hearing loss started years before his dementia diagnosis.
My wife noticed it first, she’d ask me things, and I’d miss them, or I’d think she was nagging. But really, my hearing was going. Eventually, I got tested, and they found out it was the high and low ranges I was missing.”
His hearing aids help David experience details he missed before.
With them, I can hear the birds singing when we go for a walk. Without them, I don’t hear their wonderful songs.”
The challenges of both conditions
Living with both dementia and hearing loss is challenging in ways that often compound each other, David said.
Sometimes, I’ll miss what someone’s saying, and if I can’t remember it after a few minutes, I have to ask again. It can be frustrating, and it feels like I’m asking the same thing over and over.”
His wife often helps, reminding him when he misses a word or a phrase. The effects of hearing loss and dementia on his communication can be isolating:
I think it can get you down a bit. If you keep missing things and not remembering, it’s like the world gets further away. You can start feeling more alone.”
Research has identified an association between hearing loss and dementia, and RNID’s ongoing research aims to better understand the nature of that relationship. This has raised David’s awareness about how crucial hearing care is, and he hopes that hearing and dementia research will help clarify this connection so that future generations don’t have to struggle through both.
What is research revealing about hearing loss and dementia?
Researchers are uncovering new clues about why hearing loss and dementia are linked, and how changes in hearing can affect the brain and everyday communication.
Understanding why hearing loss and dementia are linked
Professor Sally Dawson and colleagues at University College London analysed large genetic datasets to better understand why hearing loss and dementia often occur together.
Their research suggests that changes to small blood vessels may play a role in both conditions and could help explain why people with cardiovascular disease and diabetes are at greater risk. They also found that people with a higher genetic risk of hearing loss may develop dementia more quickly, providing new clues about the connection between hearing and brain health.
Prof Dawson said:
Our work suggests that there may be common mechanisms underlying the development of these age-related conditions, potentially identifying ways we could reduce the incidence of both.”
Exploring the role of blood vessels in hearing loss and dementia
Dr Nicolas Michalski and his team (Institut Pasteur, France) investigated whether changes in the brain’s blood supply could help explain the link between hearing loss and dementia.
They found that hearing loss was associated with a reduction in blood vessels in parts of the brain involved in hearing, with these changes becoming more widespread with age. Their findings suggest that blood vessels could be an important piece of the puzzle and a potential target for future treatments.
Dr Nicolas Michalski said:
Nicolas Renier and I are deeply grateful to the RNID and Alzheimer’s Research UK for believing in our novel hypothesis that the cerebrovascular network may represent a major Achilles’ heel underlying the link between hearing loss and dementia.”
“Thanks to their support, we were able to demonstrate the critical role of the vascular system and obtained strong evidence suggesting that auditory rehabilitation can prevent—or at least mitigate—vascular deterioration and thereby better protect the brain.”
How dementia changes the way the brain hears
For many people living with dementia, hearing loss can create additional challenges in everyday communication. Research led by Professor Jason Warren and Dr Chris Hardy at University College London has shown that dementia can affect how the brain processes and makes sense of sounds around us.
The team found that tests of ‘brain hearing’, including understanding speech in noisy environments, were better at predicting everyday communication difficulties than standard hearing tests. Their research also showed that changes in brain hearing can occur early in Alzheimer’s disease and primary progressive aphasia, and may be linked to cognitive decline and changes in the brain.
These findings help explain why people with dementia may struggle to follow conversations, particularly in busy environments, even when traditional hearing tests suggest their hearing is relatively good. By developing new ways to measure these difficulties, the researchers hope to improve diagnosis, assessment and support for people living with dementia.
Professor Jason Warren said:
I believe the fundamental importance of our brains for successful hearing – particularly in noisy listening environments – is still under-appreciated by researchers in the hearing and dementia communities. I really hope projects like ours will help to change this perspective – and get these communities working more closely together.”
“Particularly in the dawning era of disease modifying treatments for Alzheimer’s and widely available tests for Alzheimer proteins, it will be crucial to be able to assess sensitively and rapidly how the brain is functioning and when the onset of dementia is imminent. Our work suggests that new brain hearing tests might help us to do this – and also guide us in the design of interventions to help people with dementia communicate more effectively in their daily lives.”
Dr Chris Hardy said:
We hear with our ears, but we also hear with our brains, and dementia can affect how the brain interprets sound, even when the ears themselves are working normally. When we’re in a busy environment, such as a pub or restaurant with lots of people talking, the brain must work hard to focus on a single voice. That’s an example of the type of ability we refer to as ‘brain hearing’. ”
“This is challenging for everybody, but our RNID-Vivensa Foundation funded research shows that it’s even harder for people with a form of dementia, like Alzheimer’s disease.”
Looking to the future
While recent studies have provided important insights, researchers are continuing to explore how hearing loss and dementia are connected – and whether better hearing care could help protect brain health.
The mechanisms behind dementia and hearing loss
Dr Fabiola Paciello and her team (Universitá Cattolica del Sacro Cuore, Italy) are investigating whether hearing loss and dementia share common disease-causing mechanisms. Their research suggests that the relationship between hearing loss and dementia is bidirectional: hearing impairment can affect brain structures involved in cognition, while Alzheimer’s disease can impact the auditory system by increasing its vulnerability to ageing through oxidative stress and neuroinflammation.
These findings identify the auditory system as a target of Alzheimer’s disease pathology and provide mechanistic insight into the relationship between ageing, hearing loss, and cognitive decline.
Dr Fabiola Paciello said:
Our results could pave the way towards clinical studies to find people who are predisposed to developing dementia and to plan hearing and cognitive rehabilitation strategies for them. This will lead to more effective health solutions and disease prevention which will have a relevant impact on public health.”
Does hearing loss influence the development of Alzheimer’s disease?
Dr Daniel Llano (University of Illinois, USA) is investigating whether hearing loss can influence the development of Alzheimer’s disease. His team will explore how hearing loss affects the brain and memory, helping us better understand whether protecting hearing could also help protect brain health.
Understanding how auditory circuits in the brain interpret complex sounds – and how those circuits change with hearing loss, aging, or disease – is essential if we want to address problems like speech-in-noise difficulty, tinnitus, and the link between hearing loss and cognitive decline.”
Taking care of your hearing health
While there is still much to learn, research is helping us build a clearer picture of the relationship between hearing loss and dementia. From understanding why the conditions occur together to developing new tests and technologies, researchers are working towards a future where people can receive earlier support, stay connected for longer and live well with both conditions. Since 2018, RNID and Alzheimer’s Research UK have invested nearly £1 million in this area, helping to drive progress towards that goal.
Taking care of your hearing is part of healthy ageing. Hearing aid use has benefits for communication, social connectedness, and quality of life. These support brain health throughout life by helping people stay connected and cognitively active. Early intervention and supporting people to get the most out of their hearing aids are important to maximising the benefits for people with hearing loss.
See how our research is changing lives
Discover the hearing research we’re funding and how it’s helping us better understand hearing loss, dementia and other hearing-related conditions.