(Reuters) Teenagers are being urged to turn down the volume on their iPods after a US study found hearing problems among youngsters have risen by nearly a third in 15 years.
The study, published in the Journal of the American Medical Association, compared national surveys from the early 1990s and the mid 2000s. Each included only a few thousand teens aged 12 to 19 but was designed to represent the whole country.
In the first survey, about 15 per cent of teenagers were found by trained staff to have some degree of hearing loss. Some 15 years later, that number had risen by a third, to nearly 20 per cent – or one in every five teenagers.
"That's a few kids per classroom who will have hearing problems," said researcher Dr Josef Shargorodsky of Brigham and Women's Hospital in Boston.
"Teenagers really underestimate how much noise they are exposed to. Often the individual won't notice it, but even slight hearing loss may lead to differences in language development and learning."