Young people who listen to personal music players for several hours a day at high volume could be putting their hearing at risk, warns an expert in an editorial published in the British Medical Journal today.

Professor Peter Rabinowitz from Yale University School of Medicine says that personal music devices such as MP3 players can generate levels of sound at the ear in excess of 120 decibels, similar in intensity to a jet engine, especially when used with earphones that insert into the ear canal.

The use of these devices is high in young people - more than 90% in surveys from Europe and the United States - and "has grown faster than our ability to assess their potential health consequences," he writes.

However, evidence that music players are causing hearing loss in young people is mixed, suggesting that the true population effects may only now be starting to be detectable, says the author.

Other health effects may also need to be considered. For example, some studies have shown that use of personal music players can interfere with concentration and performance when driving, in a similar way to mobile phones.

Although evidence based guidance is lacking, Rabinowitz believes that the importance of as a public health problem makes it reasonable to encourage patients of all ages to promote "hearing health" through avoidance of excessive noise exposure.

He also suggests it would be prudent to remove while driving and performing other safety sensitive tasks, and calls for more comprehensive and ongoing surveys of the hearing health of young people.

"Personal music players provide a reminder that our hunger for new technology should be accompanied by equally vigorous efforts to understand and manage the health consequences of changing lifestyles," he concludes.