Future versions of the iPod could turn down the volume if listeners play their music at full blast for too long.

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

Experts believe that millions of young people are risking irreversible hearing damage because of the craze for MP3 players.

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.

As a result, its owners can keep their earphones in all day, risking cumulative damage to their hearing.

A new patent reveals that 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.

It states: "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."

Currently, iPods can reach volumes of more than 100 decibels (dB) - equivalent to standing 10ft from a pneumatic drill.

At that volume, experts claim there is a risk of hearing damage after just 15 minutes. 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.

However, it is unclear whether iPod owners will be able to switch off this automatic volume control.

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

In April, Apple revealed that it had sold more than 100 million iPods worldwide and it was expecting, by the end of this year, to have sold more than 4.5 million iPhones - which also function as music players - including 200,000 in Britain.

A recent report by the Royal National Institute for the Deaf estimated that more than 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.

It found that nearly 20 per cent of teenagers were listening to music for more than 21 hours a week.

Its "Don't Lose the Music" campaign also recommends using noise-cancelling headphones to avoid turning up the volume to drown out background noise.

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

Many MP3 players in Europe have had volume levels capped at 100dB after authorities in France ordered a clampdown.

Apple said it did not comment on patent applications.

Emma Harrison, head of campaigns at the RNID, said: "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."

source

Labels: Apple, Ipod

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