Some experts blame it on loud musicCHICAGO - A stunning number of teens have lost a little bit of their hearing - nearly one in five - and the problem has increased substantially in recent years, a new national study has found.
Some experts are urging teenagers to turn down the volume on their digital music players, suggesting listening to loud music through ear phones may be to blame.
Hearing loss could cause problems in school and set the stage for hearing aids in later life.
The researchers analysed data on 12 to 19-year-olds from a nationwide health survey. They compared hearing loss in almost 3,000 children tested from 1988 to 1994, to almost 1,800 children tested over 2005 and 2006.
The prevalence of hearing loss increased from about 15 per cent to 19.5 per cent.
Most of the hearing loss was "slight", defined as inability to hear sounds such as a whisper, rustling leaves, water dripping or a mother whispering "good night".
"Although speech will be detectable, it might not be fully intelligible," said the study's senior author, Dr Gary Curhan of the Harvard-affiliated Brigham and Women's Hospital in Boston.
While the researchers did not single out iPods or any other device for blame, they found a significant increase in high-frequency hearing loss, which they said may indicate that noise caused the problems.
They also cited an Australian study this year that linked use of personal listening devices with a 70 per cent increased risk of hearing loss in children.
Dr Curhan said it is unclear how loud and how long teens need to listen to such devices for hearing loss to occur.
But for iPod users, parents can set a volume limit and lock it with a code.
