I don't know if Happy Hopping is still reading this thread but I've got a pair of PX200's and when I drove up to Sydney with my family (12 hours- lots of use) I could put the volume on my md up full blast and my sister in the seat next to me could not hear a thing and I could only hear the radio or conversation when I had teh volume down at about 25%. For a $100 (AU) set of headphones that'll fit in your pocket I reckon that's pretty good.