Hull is a professor at Wichita State University and a nationally recognized expert on noise and hearing loss. He was quoted in a number of national publications a few years ago in connection with his study showing that the noise level in most aerobics classes could cause hearing loss.

Lately, he’s been asking people to lend him their ear buds, without changing the volume setting, so that he can check sound levels with his “artificial ear” testing equipment. It measures how sound is received in a human ear.

He’s found sound levels as high as 120 decibels. That, he said, is the equivalent of standing 100 feet behind a Boeing 707 at full thrust for takeoff. At that setting, your hearing can be permanently damaged after 3.7 minutes — about the length of one song.

With ear buds, “there’s no escape from the intensity,” Hull said, so the inner ear “essentially anesthetizes itself.”

It’s the same effect you get when you walk into a nightclub and think “Wow, this place is loud” but 15 minutes later don’t notice the noise. The damage is still being done.

Dangerous Decibels, an Oregon public health project, estimates that of the roughly 40 million Americans with hearing loss, 10 million cases can be attributed to noise-induced hearing loss.

To protect your hearing, Hull suggested turning your music player on full volume, then quickly backing it off about 30 percent. “That’s going to be much safer,” he said. Even at that level, give your ears a rest after an hour.

For home theater systems, consider ear protection or turn down the volume. To be sure it’s at a safe level, you can check it with a sound-level meter that will cost you about $50, Hull said. A level no higher than 90 to 95 decibels for a 1 1/2-hour movie should be safe.

And if the thought of needing hearing aids at a young age isn’t enough to deter you, Hull points out that loud noise can damage your balance as well.

“Sound can do terrible things,” he said.

By Karen Shideler
http://www.timesleader.com/mld/timesleader/living/13697049.htm