I find headphones are great when you know what you are doing and churning out more code. However when I am needing to read documentation and learn something new then I find them a hindrance.

I find myself wearing my headphones even when I am not listening to anything. It acts as a signal.

This is rubbish. You are not children.

If a coworker needs to talk to me, he sends me a message. If he really needs to talk to me, he waves his hand in front of my screen. If we are pairing on something, I obliviously don't wear the headphones or we both do and simply communicate using chat.

May I ask why?

Because you're in an open office where you are in earshot of 20 or so people.

What kind of wonderful life you must lead, where you think a question like this has any hope of being productive!