Their study found that noise exposure should be limited to 40 hours of music a week at 80 decibels — about the noise level of a busy street. It's easy to routinely listen to music above these levels. . . especially when trying to block out the noise level of, say, a busy street.
I know that 68 percent of you worry about your hearing, but do you consciously turn down the volume on your iPod as a result? Hint: to lock your volume at a certain level, go into "settings" and then "volume limit."