"We feel that, if you have a higher and longer exposure to noise, either environmental or workplace noise, you are at a higher risk for a heart attack," said lead investigator Dr. Stefan Willich.

Risk of High Blood Pressure Goes Up

Another study by University of Michigan researchers, published in the Archives of Environmental Health, found that working in a loud environment raises blood pressure levels.

They outfitted workers at a Midwest auto-assembly plant with monitors to take blood pressure readings and record noise levels throughout the day.

It was found that while blood pressure was affected by overall noise exposure, peaks in noise affected heart rate. Also, an increase of 10 decibels in average noise exposure resulted in a systolic blood pressure increase of 2 millimeters.

To put things in perspective, reducing systolic blood pressure by 6 millimeters (for the long-term) has been associated with a 35 percent to 40 percent reduction in strokes and a 20 percent to 25 percent drop in coronary disease.

Where is All This Loud Noise Coming From?

Noise from all over -- work, traffic, music, TVs, industry, people and more -- exists like never before. As a result, much of the population is now experiencing related hearing loss and other problems.

"There's no question that baby boomers have been exposed to different sources of noise than any generation before them," says Dr. James F. Battey Jr., director of NIDCD. "We're certainly seeing people in their 40s and 50s who notice their hearing is not as good as it used to be."

Younger people are also at risk of future problems, as exposure to noise via earbuds or headphones attached to MP3 players and other media devices is common.

Many people may not even realize that they are listening to music at harmful levels. An April 2005 study by National Acoustics Laboratories in Australia, published in the International Journal of Audiology, found that 25 percent of people wearing headphones who were stopped on city streets were listening at damaging volumes.

"Safe" Noise Levels

A safe average of noise for a 24-hour day is 70 dB, according to the U.S. Environmental Protection Agency. Any noise that reaches 85 dB or more can damage your hearing, but even a softer noise can harm your health if it keeps you up at night (a 45-dB noise is loud enough to keep the average person awake) or irritates you.

To put things into perspective, here's a list of some common noise measurements:

• Quiet home: 20 dB
• Normal talking: 40 dB
• Ringing telephone: 60 dB
• Air conditioner: 75 dB
• Heavy traffic: 90 dB
• Subway train, honking horns, jack hammers: About 100 dB
• Typical nightclub: 110 dB
• Ears register pain: 120 dB
• Loud music, jet take-off: About 120 dB