I'm well aware that I'm in the minority, but I have never been able to focus on anything - especially programming - other than in absolute, total silence.
(Yes, I'm an only child.)
(Yes, I'm an only child.)
I was raised in a big family, and I prefer silence when I need truly deep focus. From my experience in open floorplan offices, a majority don't break out the headphones until it gets noisy enough. Some people would even come in early or stay late for exactly this reason.