Too loud iPods could be damaging your hearing Millions of commuters risk hearing damage because they have set the volume level too high on their MP3 players.In the past, loud workplaces were blamed for causing the majority of harmful noise . However, researchers at Michigan University in the US found that noise from MP3 players has overtaken as the biggest danger to hearing.  
Occupational health experts found nine out of 10 people using public transport were exposed to excessive noise through listening to loud music through their headphones, rather than from the environment.
This could be because cheap headphones fail to seal against the ear properly, causing commuters to turn up the volume to block out exterior noise. The resulting tinny noise can drive fellow passengers up the wall.
Professor Rick Neitzel, who co-authored the study, said: 'It's startling that two in three people get the majority of noise exposure from music.
'I've always viewed the workplace as a primary risk for noise exposure. But this would suggest that just focusing our efforts on the workplace isn't enough, since there's lots of noise exposure happening elsewhere.
'It's a serious problem as there aren't really any other experiences where we would tolerate having nine out of 10 people exposed at a level we know is hazardous. We certainly wouldn't tolerate this with something that caused cancer or chronic disease. Yet for some reason we do for noise.'
Researchers looked at noise exposure among 4,500 New Yorkers who used public transport, in work and non-work related activities, MP3 player and stereo use and during domestic activities.
They found the average New York public transport user spent about 380 hours using buses and trains, exposed to average noise levels of 72 to 81 decibels.
For comparison, the average speaking level is 60 decibels, a busy street corner is 80, a circular saw is 90, a baby crying 115. The threshold for pain is about 125, and even a brief, one-time exposure above that level can cause permanent hearing loss.
Prof Neitzel said: 'Lots of people appear to be exposed at hazardous levels.
'A growing number of studies show noise causes stress, sleep disturbance, and heart disease. It may be the noise which we haven't historically paid much attention to is actually contributing to some of the top health problems in developed countries today.'