London, Dec 23: Apple may turn down the volume in the future versions of its iPod over fears that listeners could deafen themselves by playing their music at full volume for too long.

The company fears that rock fans will deafen themselves with a highest volume setting equal to a chainsaw and have led them to develop an automatic ­volume control.

This is the first time that the company has explicitly expressed fears over the risk the device poses to hearing.

According to experts, millions of young people are risking irreversible hearing damage because of the craze for MP3 players.

However, the iPod, like other digital music players, can store enough music to play for several days and has batteries that can last for more than 12 hours at a time. This leads to owners keeping their earphones in all day, risking growing damage to their hearing.

The next iPods and iPhones could automatically calculate how long a person has been listening, and at what volume, before gradually reducing the sound level, revealed a new patent.

It stated: "Since the damaging effects on users' hearing is both gradual and cumulative, even those users who are concerned about hearing loss may not behave in a manner that would limit or minimise such damaging effects. "

Presently, iPods have the capacity of increasing their volumes over more than 100 decibels (dB) - equivalent to standing 10ft from a pneumatic drill.

According to experts, there is a risk of hearing damage after just 15 minutes at that volume. Some MP3 players can exceed 120dB.

The device will also calculate the amount of "quiet time" between when the iPod is turned off and when it is restarted, allowing the volume to be increased again to a safe level, reports the Telegraph.

But, it is unclear if it will be possible for iPod owners to switch off this automatic volume control.

This move by Apple to introduce hearing protection to iPods came after heavy criticism by hearing charities who have expressed concerns about the risk posed by MP3 players.

According to a recent report by the Royal National Institute for the Deaf (RNID), approximately four million young people in Britain are at risk of hearing damage from listening to loud music, and called on MP3 manufacturers to introduce warnings and volume limits.

Listening to volumes below 70dB is considered safe, but prolonged exposure to ­volumes higher than 85dB can lead to hearing loss and tinnitus.

A number of MP3 players in Europe have had volume levels limited at 100dB after French authorities ordered a crack down.

However, Apple said it did not comment on patent applications.

"Apple's patent application makes it clear that personal audio players can damage hearing. If the next-generation iPods do what the patent claims, it could help to protect the hearing of millions of its customers, ” said Emma Harrison, head of campaigns at the RNID. (ANI)