You can't get around needing to strap things to your head when you're operating a jackhammer. Nerd at a desk? At the least we should fight for a little dignity.
There is a huge overlap in my experience between people who like open offices because it's easy for them to socialize and ask questions, and people who like to pester their busy coworkers with questions they could have figured out themselves. Also people who get bored easily and like to pester coworkers because they need a break from whatever they've been working on for the last 15 minutes.
Basically whenever I hear someone say, "I love open offices because when I don't know how to do something, my coworkers are right there to help me", I can't help but think, "yeah, I bet you do, and I bet your coworkers are ready to claw their eyes out when you come around asking something because you couldn't be bothered to read a man page". Every time someone touts coworker accessibility for questions as a critical reason to have open offices, I can't help but wonder what the ratio is between the time they spend asking other people questions and the time they spend answering other people's questions, because it always sounds like it's pretty huge.
"We should all be on the Slack/HipChat channel so we can get instant answers to all of our questions!" - the people who have lots of questions
"Great, all I need, another source of interruptions!" - the people who get asked lots of questions
(Guess which one I consider myself to be?)
Active noise cancelling systems generally only suppress continuous steady sounds, e.g. fan noise or motor hum. It actually makes conversations and other transient activities _more_ audible by reducing the background sound.
That does lead the the annoying problem that I have to have something stuck in my ear (vs on, which isn't quite as annoying) for 6ish hours a day. Also, they're expensive af, and require frequent charging since I never remember to turn off the noise cancelling when I'm done with them.