I don't get why anyone who rides public transportation doesn't wear headphones themselves. Big obvious ones are best so people don't talk to you.
I do find that the more righteous I feel about someone's actions the more annoying it becomes to me. Despite how rude it is, and you're absolutely right about that, try to not give a fuck. It really helps to consider their obliviousness as a disorder. They're pathetic.
If nothing else, hopefully it'll keep you from actually pulling the trigger one day.
I almost never wear headphones in public. I prefer the situational awareness and being able to hear "This train is skipping union square" announcements.
I'm also a guy so I don't need the "don't talk to me" signal they provide.
I looked it up trying to be helpful. Supposedly, bone conductive can overstimulate the nerve clusters - resulting in an attack of sorts. Most likely because they press on and vibrate the temples.
That really blows. I'd rather lose a finger. Sorry to learn of it.
In the spirit of the request, I would suggest beanie headphones. Assuming it's cool enough out, and you can tolerate a beanie, they may fit the bill.