Could just ONE concert or football game damage your hearing? One-off exposure to loud noise causes lasting harm, say doctors
- It was thought long-term exposure to noise was required to cause damage
- This research revolved around looking at hair cells in the ears
- Now, it has been revealed short-term exposure can damage nerve fibres
- This can make it hard to hear conversation over loud background noise
All party-goers have been warned that years of attending loud concerts and nightclubs could damage their hearing.
But now, researchers believe attending just one noisy event could be enough to cause irreparable damage.
U.S. scientists say this can leave people struggling to hear conversation over the background noise in settings such as loud restaurants and sports games.
Neuroscientists at Harvard Medical School and Massachusetts Eye and Ear Infirmary have carried out years of research into the effect exposure to noise has on hearing, Scientific American reports.
Dr Charles Liberman and Dr Sharon Kujawa found that just one evening at a nightclub can cause permanent damage to the nerve fibres that send electrical signals to the brain to allow people to hear.
They made this discovery by studying the effect of loud noises on mice, guinea pigs and chinchillas but they believe that the same can happen in humans.
They say exposure to one-off noises can wither the ends of the nerve fibres and that this breaks the connection to the hair cells across the synapses.
Dr Liberman says that every time a person is exposed to loud noises some of their nerve fibres wither.
If this only happens a few times, it will only have a small impact on hearing.
However, over time the impact can become more severe.
Dr Liberman told Scientific America: ‘You can create a visual analogy that if you down-sample the pixels in an image, you can tell if there’s something there but you can’t tell what it is.’
Until recently, the research had only been carried out on animals.
However, researchers at the Walter Reed National Military Medical Center have now begun to study hearing damage in Iraq War veterans.
And, Dr Liberman and Dr Kujawa are studying specimens of ear bones from a range of people from babies to the elderly.
They found that in older people there was evidence of a loss of nerve cells while some of the hair cells, which are what had previously been studied, remained.
This showed that just looking at damage to hair cells in the ears is not enough to establish whether hearing has been damaged.
Dr Liberman and Dr Kujawa are now researching ways of restoring damaged nerve fibres.
They are attempting to establish whether protein injections could improve hearing by encouraging withered fibres to make new synapses.
Dr Liberman also believes the findings could eventually lead to policy changes to try and protect people’s hearing.