PERSONAL stereos can seriously harm the hearing of people who have suffered middle ear infections as children, researchers have warned.
A study of young army recruits in France found a link between partial deafness and personal stereo use - but only when there was a history of childhood ear problems.
Hearing tests were given to 1,208 men aged 18 to 24 undergoing army medical examinations.
They revealed that 17 per cent of those who used personal stereos for at least an hour a day had a reduced ability to detect sounds over the whole human hearing frequency range.
Further analysis at a research centre in Lyon showed that personal stereos had no effect on men without a history of ear infections.
For those who had suffered infections, the loudness threshold at which they could hear sounds was on average 11 decibels higher than normal. 'This difference of susceptibility to personal stereo use was significant,' the researchers wrote in a letter to The Lancet journal.
Personal stereos also increased the risk of ringing in the ears in these individuals.
The study showed that the hearing threshold at low frequencies was slightly increased in 38 per cent of men who went to rock concerts and discos twice a month or more. …