Headphones are truly interesting. Traditionally, they are considered to radiate an antisocial vibe, which makes sense if you think about it. If you've got a Walkman or other portable music device of your choice handy, plug a pair of headphones into it and put them on. Now take a look at yourself in a mirror or other shiny object. The headphones are covering (or plugging) your ears, so some might say that wearing them screams out "LA LA LA, I can't hear you, don't talk to me." This makes sense, sure, but is it really true?
Much like smoking a clove cigarette often prompts inquiring minds to ask what it is, wearing headphones, especially if they're a little on the loud side and people around can hear your music, can be almost taken as an invitation, "Go ahead. Ask me what I'm listening to," providing the chance to expose another person to the obscure artist of your choice.
So what's the signal they give off? Do they say "leave me the fuck alone," or "talk to me?" Take your pick...