‘Tough ears’ in old age
Chewing, talking or singing might help protect your hearing, an Australian researcher has suggested. Dr Andrew Bell from the Research School of Biology at the Australian National University, recently told ABC News the small sounds made by these actions may possibly activate tiny muscles in the ear which in turn “muddles loud sounds”.
Chewing, talking or singing might help protect your hearing, an Australian researcher has suggested.
Dr Andrew Bell from the Research School of Biology at the Australian National University, recently told ABC News the small sounds made by these actions may possibly activate tiny muscles in the ear which in turn “muddles loud sounds”.
The study, published in the Journal of Hearing Science, revealed conventional models of hearing do not explain why contracting the muscles of the ear — which some people do voluntarily – can reduce sound by 30 decibels.
However, Dr Bell suggested the answer lies in a “discarded 19th century theory” meaning the middle ear muscles work like a hydraulic pump, which may explain why some people seem to have ‘tough ears’ impervious to hearing loss while others are more sensitive.
The middle ear consists of three tiny bones — including the smallest bone in the body — two miniature muscles and tendons.
“If you close your eyes tightly you’ll hear a fluttering sound and that’s your middle ear muscles at work,” Professor Bell said.
Under current theories of how the ear muscles work, the muscles and bones of the middle ear stiffen up in reaction to a loud noise, dampening sound waves that travel into the cochlea where fine hairs detect the vibration.
“Obviously [the bones and muscles of the middle ear] have got some sound control function because they’re activated when the sound gets loud,” he added.
Instead, the ‘pressure theory’ proposed the middle ear muscles work like a hydraulic pump, pushing the last bone into the cochlea and increasing the pressure of the watery fluid that fills it. In turn, that pressure squeezes the sensing cells inside and reduces their sensitivity.
Professor Bell claimed a better understanding of this mechanism may help prevent hearing loss, while adding that ways of making the middle ear muscles more activated could, as a result, be discovered in the future.
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