A study by several leading hearing experts offers guidelines to safe listening of IPods. They reported, according to Digital Music News, that the average person could listen to the IPod for 4.6 hours a day at 70 percent of its maximum volume without increasing the risk of hearing loss. A separate study took into account types of earphones used and the environment in which the subjects listen to music. In a noisy environment, 80% of students listened to music at risky levels, compared to only 6% who turned the volume to levels increasing the risk of hearing loss in quiet surroundings.
I'm sure it is an indication of my age, but I have thought for quite a while now that we are likely to one day have a whole generation of hearing impaired individuals. I wasn't basing this on the levels at which individuals listen to IPods but rather the volume at which music is played in some teenagers cars. I wonder if a study has been done about that?