The Sound of Ageing: Why Better Acoustics Matters for Hearing, Connection and Dementia Care
Hearing is now recognised as one of the largest modifiable risk factors for dementia. That makes the acoustic environment a public-health consideration, and turns sound itself into something we can design to help.
An elderly relative goes quiet at family gatherings. They stop following the conversation, sit slightly apart and eventually stop coming.
We tend to interpret this as withdrawal: a natural narrowing of the world that comes with age. Often, it is something simpler and more fixable. They cannot hear.
For a long time, age-related hearing loss was treated as an inconvenience rather than a serious health matter, something to tolerate and, eventually, perhaps address with a hearing aid. Over the past decade, however, the growing body of evidence connecting hearing to brain health, and specifically to dementia risk, has changed the conversation.
The acoustic environment is no longer simply a question of comfort. It is increasingly a question of population health.
The scale of the challenge
The demographics help explain why this matters now.
The World Health Organization estimates that around 55 million people worldwide live with dementia, with nearly 10 million new cases each year. As populations age, that number is projected to reach 78 million by 2030 and 139 million by 2050. More than 60% of those affected live in low- and middle-income countries, where care infrastructure is often at its thinnest.
There is currently no cure for dementia. That is precisely why prevention has become a central focus of research, and why interventions capable of reducing or delaying risk, even modestly, are significant.
Where acoustics enters the picture
In 2024, the Lancet Commission on dementia prevention, intervention and care published its updated analysis of modifiable risk.
It identified 14 factors which, if addressed throughout the course of a person’s life, could in principle prevent or delay nearly half of dementia cases worldwide. Among these factors, hearing loss carried the single largest population-attributable fraction, estimated at 7%.
That figure must be handled carefully because it is easy to overstate. It does not mean that treating hearing loss would eliminate 7% of dementia cases. It means that, within the Commission’s modelling, hearing loss is associated with a larger share of dementia risk than any other single modifiable factor.
Hearing is therefore the largest modifiable lever we can currently reach, not a switch that turns the problem off.
Association is not the same as proof
This is where the evidence demands honesty and where well-meaning commentary can sometimes go too far.
The relationship between hearing loss and dementia is strong and consistent across observational studies. Whether treating hearing loss prevents cognitive decline is a separate question, and the answer is more measured than some headlines suggest.
The clearest test to date is the ACHIEVE randomised trial, published in The Lancet in 2023. It followed nearly 1,000 older adults with untreated hearing loss over three years.
Across the study population as a whole, the hearing intervention did not result in a statistically significant slowing of cognitive decline. However, in a pre-specified subgroup of participants already at greater risk of decline, the intervention slowed cognitive change by 48% over the three-year period.
Read carefully, this is encouraging rather than conclusive. It suggests that hearing intervention may be most beneficial for those already at greater risk and that any benefit is conditional. It does not support the blanket claim that hearing aids prevent dementia.
Stating that distinction clearly matters. Overselling the science risks undermining otherwise valuable evidence.
Why hearing may matter to the brain
Several proposed mechanisms help explain the association between hearing loss and cognitive health. They also point towards areas in which design can help.
Increased cognitive load
When the ear delivers a degraded signal, the brain must devote more of its resources to decoding speech. Those resources would otherwise support memory, attention and thinking. Maintaining that additional effort can be exhausting, particularly over many years.
Social withdrawal
People who find it difficult to follow conversations may gradually disengage from them. This can lead to reduced participation and social isolation, which is itself an established dementia risk factor.
Reduced auditory stimulation
Hearing loss may also reduce stimulation of the auditory pathways and connected areas of the brain.
None of these mechanisms is purely medical. Each is influenced by the environment in which a person is listening.
A room that makes speech easier to understand can reduce cognitive load, support conversation and help people remain socially connected. This is where acoustics stops being a bystander in the dementia story and becomes part of it.
The environments in which we age
Consider the places in which many older people spend their time: care homes, day centres, hospital wards and communal areas within retirement housing.
These can be acoustically demanding environments, with hard surfaces, long reverberation times and a continuous layer of alarms, trolleys, televisions and overlapping voices. Reported noise levels in living, dining and resident rooms within nursing and dementia-care facilities have ranged from approximately 54 to 67 dB. This is a demanding background for anyone, but especially for a person whose hearing or cognition is already under strain.
The consequences extend beyond discomfort. Research into dementia-care environments has identified links between uncontrolled noise, agitation and the behavioural and psychological symptoms of dementia.
A person living with dementia may retain normal hearing sensitivity but lose some ability to interpret what they hear. In that situation, a noisy or reverberant room can become not only tiring, but genuinely confusing and distressing.
What good acoustic practice looks like
These are solvable design problems. The discipline and tools required to address them already exist.
Good acoustic design for ageing and dementia settings rests on several established principles:
- Control reverberation so that speech remains intelligible instead of becoming blurred by reflected sound.
- Manage noise at its source and between spaces so that corridors, alarms, building services and neighbouring rooms do not unnecessarily intrude upon rest or conversation.
- Design for the purpose of each space, recognising that dining rooms, quiet lounges, treatment areas and bedrooms have different acoustic needs.
- Measure real-world performance rather than assuming a completed space functions as it was designed to function.
None of this is exotic. It is the established toolkit of acoustic engineering applied in settings where the stakes are unusually high.
However, there is a further step that expands what these environments can offer.
From controlling noise to designing sound
Acoustic practice has traditionally been subtractive. The aim has been to remove or reduce unwanted sound: less noise, less intrusion and less reverberation.
That remains essential, but it is only one part of what a space can offer. We should also ask what sounds ought to be present, rather than focusing exclusively on what should be removed.
This is the principle behind soundscaping: treating the sonic environment as something that can be actively composed and designed, rather than simply quietened.
Evidence emerging from dementia-care research points in the same direction. Studies indicate that introducing calming and familiar sounds, such as birdsong, water or gentle human activity—may improve mood and reduce agitation. A silent room is not necessarily the goal. A supportive one is.
The next step is to make that soundscape adaptive, allowing it to respond to the space and the people within it instead of playing the same sound regardless of circumstances.
This was the focus of a Knowledge Transfer Partnership between KP Acoustics and the University of Salford. The project developed an AI-enabled soundscape system that manages sound within a space in real time rather than passively masking it. It was graded Very Good by Innovate UK, and the technology has since been taken into new settings, including a shortlist to develop soundscape installations at Heathrow Airport.
The potential relevance to ageing and dementia care is direct. A system capable of tailoring an acoustic environment to its setting and adapting throughout the day could support care homes, hospital wards and retirement communities, places where the right sound at the right time may reassure a resident, while the wrong sound may cause distress.
Personalised and responsive soundscaping is how the principle of designing sound, not merely removing noise can become a practical tool in the places where people grow older.
Designing for hearing, conversation and connection
The story of dementia is often presented principally as a medical one, centred on the search for a cure that has not yet arrived. But a meaningful part of the story is environmental, and that part is available to us today.
We cannot yet stop dementia. We can address one of its largest modifiable risk factors, and we can design the places in which older people live and receive care so that hearing is easier, conversation remains possible and connection lasts longer.
That is not a small contribution for a discipline that often goes unnoticed. Acoustics is becoming infrastructure—and nowhere is that clearer than in the environments we create for later life.
About the author
Dr Kyriakos Papanagiotou is the Founder and Director of KP Acoustics Group, an independent acoustics consultancy working across noise, vibration and the built environment. Through KP Acoustics Research Labs, the Group also undertakes research and innovation focused on the future role of acoustics within buildings, communities and everyday life.
How KP Acoustics can help
KP Acoustics supports care providers, healthcare organisations, designers and project teams in understanding and improving acoustic environments. Our work spans acoustic assessment, building design, measurement and research-led soundscape solutions.
To discuss the acoustic needs of a care, healthcare or later-living environment, please contact our team.
To find out more contact KP Acoustics at info@kpacoustics.com or call 0208 222 8778
References
- World Health Organization. Dementia: fact sheet.
- Livingston G, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet, 2024.
- Lin FR, et al. Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial. The Lancet, 2023.
- Talebzadeh A, et al. Effect of Soundscape Augmentation on Behavioral Symptoms in People With Dementia: A Pilot Randomized Controlled Trial. Innovation in Aging, 2024;8(9).