Even if burn in is a total myth, there's no way it's going to hurt. Telling people not to is audio-intellectual imperialism in the first degree. I don't see a single downside if someone wants to use test tones or pink noise or whatever. Personally, I leave my library playing on random for a couple days straight whenever I get a new piece of equipment (and I listen during the process -- no way I'm going to wait until it's "done")... but I don't really have an opinion on whether or not this helps. I just see 0 reason not to give it a shot.
There are valid reasons go think that burn in happens for devices that use tubes or capacitors. For headphones, I do not know. But I really see no reason to care. Just listening normally will cause burn in over time, and trying to speed the process up with little rituals causes no harm.Edited by manbear - 11/17/13 at 2:15pm