Larry Magid, ConnectSafely.org/SafeKids - "If you have kids, chances are very good that they are listening to music through earbuds or earphones. No problem with that, but if the volume is too high, it can affect your child’s hearing. That’s why it makes sense to equip them with headphones or earbuds that limit the volume to about 85 db or less."
"I’m no audiophile, but I do love music and what I heard sounded good to me."
"...they also block out a lot of ambient noise even though they don’t have any active noise canceling technology."