the pads are, but not the fabric on top of the headphone drivers. Hoewver, the pads are not entirely fabric, i think they're padded with foam, and then the underside of the pad is pleather (plastic leather), i dont think putting them in the wash would be such a good idea... Ill check out...
I just got a pair of headphones (Sony D66 Eggos) off a guy from antoher forum, and the pads as well as the fabric covering the surface of the driver smells like... well, somebody else and not me... I tried febrezing it, and then putting it near an open window to let it air out, but no luck...