When practicing, I usually play to minus-drum mp3 recording of my band's originals, or click tracks saved on my mp3 player. For this reason, I use my trusty Sennheiser HD250 (medyo entry level) closed headphones, and my cheap-o (but surprisingly decent) A4-Tech in-ear/canal earphones. I once tried wearing the IEM's to a gig, and yes, they isolated sound effectively. But not to the point where I couldn't hear the guitars and bass.