A mom invented iHearSafe earbuds because she was worried about the effect of iPods on her kids’ hearing.  They can be used on any music player and limit the volume to 80 decibels.  Lowering the volume for kids is good not only because it will reduce the risk of hearing loss, but also because it will allow them to hear outside sounds, making them more aware of their environment.  Of course, these earbuds are a good idea for adults, too.