As many as a quarter of today's teens could start losing their hearing in their thirties, say Tel Aviv University researchers studying the effects of MP3 players.
"In 10 or 20 years it will be too late to realize that an entire generation of young people is suffering from hearing problems much earlier than expected from natural aging," says professor Chava Muchnik.
Muchnik's team studied 289 13 to 17 year olds, who were asked about their habits on personal listening devices (PLDs) — specifically, how loud they tended to set the device, and how long they usually listened for.
They then measured these listening levels for 74 teens in both quiet and noisy environments - and what they found was worrying, says Muchnik.
Eighty percent of teens use their PLDs regularly, with 21 percent listening from one to four hours daily, and eight percent listening more than four hours consecutively.
Taken together with the acoustic measurement results, this indicates that a quarter are at severe risk of hearing loss. And because hearing loss is a gradual process, the chances are they won't notice until it's too late.
Teens should choose over-the-ear headphones instead of the ear buds that usually come with an iPod, says Muchnik - but manufacturers should get involved too.
Currently, many countries have no regulation over noise volume beyond work-related health and safety rules. But Muchnik recommends that manufacturers should adopt the standards used in Europe, which stipulate a maximum output of 100 decibels - output can rise as high as 129 decibels in the US and elsewhere.