You can always tell an audiophile by the headphones they wear. If you see someone on the train or bus with something that looks like an aircraft headset on his ear, it's not because they're a geek, it's because they appreciate good music. Those big aircraft headset look alike are noise-cancelling headsets. There's a reason why these headsets are big and padded. The padding reduces the background noise, that's why airplane pilots have similar looking headsets. Noise cancelling headphones also creates antinoise to reduce background noise and the main advantage of this is that these headsets lets you listen to your music at lower levels to reduce the strain on your ears.

Bose, Sony, JVC, and Sennheiser makes some of the top quality noise cancelling headsets, however, these headsets don't come cheap and most of them look like David Clark headset (popular headset for pilots). There are new models nowadays that are not as bulky but some say they are less effective. If you're serious about your music, try investing in some good quality headsets. CNET has a list of their top noise-cancelling headsets if you need a comparison.