Re: Whilst I've toyed with the idea...
My belief is that anyone wearing earbuds or headphones on a public access way has not only provided consent to being run over, but is actively requesting it, and i make a token effort to avoid doing so merely to disappoint them.
I used to wear various back-of-head headphones, down around my neck, just to get speakers relatively close to my ears without obstructing them.
These days I just hang a bluetooth speaker off my handlebars (bicycle) or belt (afoot in 'wilderness'), and use an innocuous playlist whilst urban, saving my psychedelic-black-metal-in-foreign-languages for ... most of the time I am at work ...
I consider it to be a safety feature, increasing others awareness of my proximity, or allowing wild animals to vacate the area. (I suspect Evanesence is less useful for chasing away snakes than Rammstein or Disturbed, and feral cattle seem to be fascinated by Orransi Pazuzu, Data collection is ongoing.)