clinical focus
industry
& reform
Listen up!
Hearing aids may be key to
slowing cognitive decline.
By Louise Durack
D
elaying cognitive decline and
improving brain function in older
adults with the use of hearing aids
has been the focus of new research.
Cognitive decline is associated with
hearing loss, which affects about 32 per
cent of people aged over 55 years, and
more than 70 per cent of people aged over
70 years. Hearing loss has been identified
as a modifiable risk factor for dementia.
The study, conducted by the University
of Melbourne, tested the use of hearing
aids in almost 100 adults aged 62–82 with
hearing loss.
Participants were assessed before and
18 months after having hearing aids fitted to
test their hearing, cognitive function, speech
perception, quality of life, physical activity,
loneliness, mood and medical health.
“After 18 months of hearing aid use, we
found that speech perception, self‑reported
listening disability and quality of life had
significantly improved for participants,”
said the study’s chief investigator Associate
Professor Julia Sarant.
“Notably, of a subset of those 100
people who were assessed, over 95 per
cent showed either clinically significant
improvement or stability in executive
function – their mental ability to plan,
organise information and initiate tasks.
14 agedcareinsite.com.au
“This was a very pleasant and
unexpected surprise for us, as an
improvement in cognitive decline in adults
is not something that we normally see,”
Sarant said. “I had actually expected to see
stability in this group, but definitely not
improvement.”
Women, in particular, showed significant
improvements in working memory – used
for reasoning and decision-making – as
well as most other cognitive functions
assessed.
The study also found more frequent use
of hearing aids was associated with greater
improvements in cognitive function,
and women were much more diligent at
wearing the devices than men.
“Although there are successful treatments
for hearing loss, there is currently no
successful treatment for cognitive decline
or dementia,” Sarant said.
She said that older people generally lose
about two decibels of hearing per year
and referred to previous research from the
Lancet Commission in 2017 showing that
hearing loss is accountable for 9 per cent
of the modifiable risk factors for dementia.
“While we don’t really totally understand
the link between hearing loss and
dementia, with regards to increased
listening demands for someone with a
loss, it has been seen that the brain does
not just use the auditory cortex (which we
are supposed to use), but also other parts
of the brain to assist with comprehension,
sound and speech. And this may take
away the brain’s ability to deal with other
cognitive functions. Basically, they may be
having to use more of their brain to listen.
“We also know that someone with a
mild hearing loss has double the risk of
developing dementia; someone with a
moderate loss has almost three times the
risk of developing dementia; and someone
with a severe hearing loss has almost five
times the risk. All the evidence points to the
fact that if you have an untreated hearing
loss, you will unfortunately see a faster
speed of cognitive decline.”
Sarant acknowledged that there are
barriers to hearing aid use which are
sometimes seen in settings such as
aged care.
“Within aged care homes there are
obviously a lot of people with hearing
issues, and the onus cannot always be
placed on residents to manage their
hearing aids with regards to remembering
batteries, finding the aids, setting them up,
and so on. Therefore, it does require effort
by staff to help manage the use of them.”
Sarant said the latest research is a
positive step in investigating the treatment
of hearing aids to delay cognitive decline,
but that further research is needed.
“Further studies are underway to
compare cognitive outcomes from a larger
sample size with those of a healthy ageing
comparison group of older Australians with
typical hearing for their age,” she said.
The study was published in the Journal
of Clinical Medicine. ■