“Even when I'm not listening to music, people don't bother me when I'm wearing them.”

I've never found this to be true. In fact, I find it less annoying if I don't bother wearing them and deal with the interruptions rather than put mine on and have someone come up to my desk every 10 minutes.

That being said, the article is spot on. The only way to get into flow in an open office situation is to minimize ambient noise.