Study: Hearing gets more tiring for the brain as we age
With support from Sonova, a recent and globally unique study by the University of Zurich has been looking at the consequences of age-related hearing loss in the brain. The study has allowed neuropsychologists to visually map and measure the consequences of age-related hearing loss in the brain.The results show that although the ageing brain requires intensive training in order to regain a better understanding of speech when using hearing instruments, an ageing brain can still relearn how to process speech. This supports the belief that hearing does not just take place in the ear, but also as a cognitive process in the brain.
[divider]Age-related hearing loss[/divider]
It is entirely normal for the human body to deteriorate as it ages, a process which also affects the hearing leading many people to eventually need a hearing aid. Historically, age-related hearing loss was attributed to just the exterior wear and tear within the cochlea but science has more recently found that hearing loss is also attributed to how the brain processes speech, a process which becomes more difficult with age.
[divider]The Study[/divider]
The two-and-a-half year study investigated how well and how quickly the brain is able to learn in older age. The study is unique as it represents the first successful long term study that scientifically measures the efforts the brain makes to react to language. It involved 15 younger and 45 senior participants who took part in regular hearing tests over a period of several weeks. This included both hearing aid wearers and people without any hearing loss.
“We wanted to know how the brain is able to process speech in old age and also how it is able to re-learn this ability, especially when the person has been affected by hearing loss and wears hearing aids,” says Nathalie Giroud, who is studying for a doctorate in neuropsychology at the University of Zurich.
Test subjects were asked to distinguish between various syllable pairs, sometimes under difficult conditions. The syllables often only differed by one very similar sound in a high-frequency range. Electrodes were attached to the scalps to detect and conduct the brainwaves, which were then digitised using an EEG (electroencephalograph). This allowed researchers to measure the neuronal effort, or how many brain cells were activated to determine the difference between the syllables.
[divider]The Results[/divider]
Whilst distinguishing between the various syllables, older test subjects affected by hearing loss struggled to detect the contrast. The group of younger test subjects required less brain activity to hear the difference between syllables. Older participants without hearing loss were found to require more brain cells to be activated whilst those participants experiencing hearing loss showed neuronal effort that was even more detectable. However, the study confirmed that all test subjects were able to improve their performance during the 3-month screening period.One of the most crucial findings from the study was that with older people experiencing hearing loss and wearing a hearing instrument for the first time or even those who update and change their hearing instrument, the brain needs atleast 12 weeks of intensive training in order to process speech nearly as well as it did before. Many people expect hearing instruments to work perfectly immediately, but this study has scientifically confirmed a finding that audiologists have known for a long time about daily experience, some patience is required.
This has made clear that we have to redefine hearing loss and can no longer reduce it exclusively to age-related damage to the inner ear.
The study is significant because it has confirmed that even an ageing brain can relearn how to process speech - hearing and understanding are not just carried out by the ears but also take place in the brain.
[divider]Why is this significant?[/divider]
Research such as this support how we at Cubex already approach hearing care, looking at the entire cognitive process of hearing to support people to regain their ability to understand speech, maintain their cognitive faculties and participate in an active life. Hearing treatment plans are highly personalised at Cubex, taking into consideration the individuals hearing and unique cognitive and communication ability.
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[divider]More about Sonova[/divider]
Sonova is the leading developer of innovative hearing care solutions - from hearing aids to cochlear implants to wireless communication solutions - one of it's core brands being Phonak. To learn more about about the latest key hearing treatment technologies developed under Sonova’s Phonak brand click here.