At those levels, says Ray Hull, professor of communicative disorders and sciences at Wichita State University, you can listen to the sound for about five minutes before you risk permanent damage to your ears. Hearing danger can come from the unlikeliest places, including, ironically, from activities that are explicitly meant to keep you healthy. A study from the mid-1990s found that 80 percent of the health clubs and fitness spas surveyed cranked up the music in group exercise classes from 105 to 110 decibels, and a few exceeded 120 decibels. IDEA, the association of fitness professionals, recommended that its 23,000 members lower the volume, but a follow-up study last year revealed that nothing has changed. Once you have all the pieces of cardio equipment going, you've got to be able to hear over them.
Some people are actually addicted to listening to loud music, a new study shows.
But toxic noise is not always voluntary. The shelves in Nadler's office at the League for the Hard of Hearing are lined with toys, some testing as loud as 135 decibels with a sound meter. Even if the toys don't sound as loud to adults, Nadler argues that kids tend to hold them up to their ears when they play. While there is no clear evidence that children's ears are more vulnerable to noise than adults', children have more to lose, notes Laurie Hanin of the League for the Hard of Hearing. Interestingly, personal stereo systems with headphones do not pose a substantial threat to hearing, most audiologists say, even though they can reach 112 decibels and seem permanently attached to some teenagers' heads.