content: I tried these with my MP3 player all the way up with a Boostaroo headphone amplifier and the volume on the speakers all the way up inside a closed full face HJC helmet- still couldn't hear much of anything. I was sitting still on my 500cc Aprilia Scooter- probably the quietest "motorcycle" out there. I'm far from deaf and my $10 Sony over the ear sporty buds are pristine under the same conditions- save your time and money and head to Walmart. I'm mailing them back tomorrow. (the Boostaroo does help with regular earphones/buds to get over the bike and wind noise.)