There are many  assumptions when it comes to dementia – the number one being that nothing can be done to delay it, or reduce its effects, says Audiologist and owner of Value Hearing, Christo Fourie.

Mr Fourie says most people consider dementia to be an inevitable consequence of ageing, but given that it’s one of the world’s biggest health concerns, it’s important to dig a little deeper.

“It is important to look at all the factors we can control, to ensure that we remain in the best possible health for the longest time possible,” says Mr Fourie.

One of those factors, he says, is hearing, with new scientific research showing that improving hearing is positively associated with a reduction in cognitive decline and dementia.

“In fact, an Australian white paper released in March this year, examined 100 studies and concluded that unaddressed hearing loss was responsible for more dementia among older adults than other risk factors, including alcohol overconsumption, traumatic brain injury, obesity and hypertension combined.

“This peer-reviewed white paper backs up a 2017 report in the Lancet which identified nine potential risk factors for dimension named the greatest of these risks was hearing loss.

“The Lancet identified midlife hearing impairment as a risk factor for dementia and a follow up study published in 2020 said addressing hearing loss was the number one modifiable risk-factor in dementia prevention.

“A 2018 report from the University of Manchester, showed cognitive decline slowed after a patient’s hearing and sight were improved. The rate of decline halved following cataract surgery and was 75 per cent less following the use of hearing aids.”

A current study at the University of Melbourne is also showing some encouraging results, indicating that hearing aid use is directly correlated with improvement in cognitive function.

The amount of improvement is correlated with the amount of hearing aid use.

“The aim of a hearing aid is to improve the clarity of speech in a challenging listening environment,” says Mr Fourie.

“Hearing aids achieve this by amplifying speech sounds and minimising annoying background sounds through advanced noise reduction systems.

“Improving the clarity of speech in noisy environments places less strain upon the brain and allows people to engage in group conversations.”

Hearing loss can also be misdiagnosed as dementia due to common symptoms of both conditions overlapping, such as confusion during conversation, changes in methods of communicating, difficulty completing everyday tasks, and feelings of fatigue or stress.

“As a result, hearing loss can be misdiagnosed as dementia or make the symptoms of dementia appear worse.

“The part of the brain associated with long-term memory for places and events, is also involved in short-term storage and manipulation of auditory information.”

Even mild hearing loss comes with increased risk of cognitive decline - 1.89 times greater than no hearing loss.

“One hypothesis is that hearing loss forces the brain to spend precious resources on decoding the message rather than on critical elements of cognition such as problem solving and memory.”

Around 3.6 million Australians are estimated to have hearing loss, with men more likely to be affected than women. Half of all men will have a degree of hearing loss by the age of 50. That number rises to over 90 per cent for men over 60. For women, the rate jumps sharply for the over 60s with 70 per cent of women having hearing loss.

Typical signs of hearing loss include:

• Difficulties in following conversations in noisy environments.
• Difficulties in hearing softly spoken people and particularly women's and children's voices.
• Difficulties in hearing someone on the telephone.
• Asking people to repeat themselves more than usual.
• Complaints from family members that the television is turned up too loud.
• Feeling more tired than usual after straining to hear conversations.
• Hearing better when facing a person than when you are not.

If a person is having signs of dementia, it’s important to rule out hearing loss by undertaking a hearing test.

“People may not know that we don’t actually hear with our ears, we actually hear with our brain.

“The ears transfer the sound which is converted to electrical signals which are sent to the brain to interpret.

“The longer the brain goes without hearing the full range of sound - like that found in speech -  the more difficult it becomes for the brain to correctly interpret the sound and its meaning.

“The neural pathways associated with hearing tend to deteriorate with hearing loss. So, addressing hearing loss early can be helpful in reducing the dementia risk.”

Mr Fourie believes more education is needed around the link between hearing loss and dementia.

“I would like to see greater awareness of speech-in-noise testing and the importance it plays in a more accurate prescription for hearing aids.

“I would also like to see cognitive screening assessments become more readily available from a range of allied health professionals

“Typical hearing tests include speech in quiet, but it is speech in noise - where the brain has to work to filter out competing sounds - which is so important. Unfortunately, only a few audiologists in Australia perform this test.”