Well insulated, so that the wearer is the only one around who cant hear the recording. For use in rooms when someone has a headache. Ha.-- Blumster, Jan 22 2005 How would you insulate it so that the wearer couldn't hear the music via the vibrations travelling throughout the earpiece?-- pooduck, Jan 22 2005 Noise cancellation.-- Blumster, Jan 22 2005 Input talking books.-- skinflaps, Jan 22 2005 random, halfbakery