Many of us recognise the situation. You are sitting in a restaurant and struggle to make out what the person opposite you is saying, even though a standard hearing test may look completely normal.
A new study, published in JAMA Otolaryngology-Head & Neck Surgery, suggests that precisely this ability, sorting a conversation out from background noise, the so-called "cocktail party effect", could be an early signal of changes in the brain.
The researchers found that people who had more difficulty perceiving speech in noisy environments developed faster thinning of the cerebral cortex in areas that are important for language and attention. The association remained even after accounting for traditional hearing loss and hearing aid use.
It is important, however, to put the results in perspective. The study is relatively small and the findings need to be confirmed in larger studies before any firm conclusions can be drawn.
The most important message is therefore perhaps not the study itself, but what we already know from before.
Hearing loss is today one of the most important modifiable risk factors for dementia. Research shows that older people with hearing loss who use a hearing aid have around 20 percent lower risk of developing dementia or cognitive impairment compared with those who do not treat their hearing.
The new study therefore raises an interesting question: could tests of how the brain perceives speech in noisy environments become an early behavioural sign of increased vulnerability in the brain, long before memory problems arise?
At Executive Health we follow developments in this field closely. Much suggests that early detection is important in brain health as well.
Source: JAMA Otolaryngology-Head & Neck Surgery.
