European scientists have sounded the alarm about the dangers of using digital music players, warning that listening to them too long and too loud can cause permanent hearing loss.

Five to 10 per cent of the people who listen to an MP3 player for more than one hour per day each week at a high volume risk permanent hearing loss, they found.

That means that between 2.5 million and 10 million people are at risk, according to the panel of scientists who conducted the study at the request of the European Commission.

EU rules already restrict noise levels from such MP3s to 100 decibels, but the European Commission said that there was growing concern about excessive exposure to such devices, especially among youths.

The scientific panel found that people who listen for only five hours per week with a volume above 89 decibels would exceed the current limits in place for noise allowed in the workplace.

Users listening for longer periods risk permanent hearing loss after five years, according to their findings.

The European Union’s executive arm estimated that there are roughly 50 to 100 million people who may be listening to portable MP3 music players on a daily basis.

It said that a 184-246 million portable audio devices had been sold over the past four years, including 124-165 million MP3 players.