A new study has found that 9 out of 10 city dwellers may have enough harmful noise exposure to risk hearing loss and much of that exposure comes from commonly used MP3 Players.

Learning that level of sound from MP3 players is louder than that of a loud work environment was a shock to researchers themselves, according to Rick Neitzel, assistant professor at the University of Michigan School of Public Health and the Risk Science Center.

As an occupational hygienist, Neitzel said he was surprised by the findings and expected regular users of trains and buses along with work related activities to be the “chief culprits in excessive noise exposure.”

In examining the contribution of common noise sources to total annual noise exposures in 4,500 New York City residents who use public transportation, the researchers found that 90 percent of transit users and 87 percent of nonusers exceeded the recommended noise exposure limits, mostly due to MP3 and stereo usage.

"That two out of three people get the majority of noise exposure from music is pretty striking," Neitzel said.

"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."

Neitzel believes it’s a problem and can be harmful.

"I do think it's a serious problem, 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 another agent, such as something that caused cancer or chronic disease. Yet for some reason we do for noise."

Neitzel suggest that noise may contribute to much of today’s health problems.

"Lots of people appear to be exposed at hazardous levels," he said.

"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. This begs for a public health education program."