Health professional are becoming increasingly concerned about the volume of the music on MP3 players and whether it could be damaging people's hearing.

You see them everywhere, on buses, at the gym and out on the streets. Digital music players have become the biggest tool in the fight against boredom.

But the ubiquitous nature of the players seems to have left many deaf to the risks.

So exactly how loud is the volume on iPods and MP3 players getting, and when does it hit the danger zone?

Many of the 9,000 full-time students at Conestoga College rely on music to get through the day.

So Calvin Staples, an audiologist and the Hearing Instrument Specialist program co-ordinator at Conestoga College, helped CTV test the audio levels some of those students are using.

"If you listen to your iPod at the maximum setting now, at about 100 decibels, 15 minutes can damage your hearing," Staples says.

In fact, Ontario Workplace Safety standards mandate that occupational noise should be no greater than 85 decibels (dB) over the course of an eight hour workday.

But music players can put out upwards of 95 to 105 dB, and the higher it gets, the sooner the damage can set in.

Of five random Conestoga students whose music players were tested, Staples found three were in the danger zone.

"So about a 10 dB range between 100 and 110 dB, which is fairly loud. You're looking at about 15 to 10 minutes of wear time before it can cause some damage to your hearing."

He says while the hearing loss may be temporary and hard to notice at first, over time those who continue listening at that volume may start to suffer more permanent damage.

Health Canada says personal stereo systems are capable of having an impact on someone's hearing and cites a recent European report that found that five to 10 per cent of listeners are at risk due to prolonged high sound levels.

"What we are also finding is that they just don't care, they really don't care," Staples says. "They think it's their own personal choice, if they want to listen that loud then that's their prerogative."

Students who spoke with CTV say they don't think about hearing loss and aren't planning to turn things down anytime soon.

And that's a concern for a young age group sometimes dubbed the iPod generation.

The noise damage seems to be starting at a much younger age, with some studies finding children as young as 12 showing increased signs of hearing loss.

Coming up in part two: Find out how loud MP3 players can go and how that compares to everyday noises.