While I am not interested to argue just for arguements sake, but I believe headphones are similarly either unbalanced or balanced based on the amt of rings on the jack. For ex: a TRS (tip+ring+sleeve) is balanced and a TS (tip+sleeve) is unbalanced. Just like on guitar cords (unbalanced 1/4 outs with TS) vs typical speaker 1/4 outs that are TRS. And, of course, a TRRS is also unbalanced. yada yada yada...