And how does your vision help to hear traffic/pedestrians/cars/dogs/children that are usually audible before being visible?
Also, it's a good idea to be able to listen to your sounds that your bike makes indicating a mechanical problem, etc.
Also, usually the ones wearing earbuds are oblivious about their surroundings, like these stupid slow joggers running in the middle of the bike lane with earbuds in, so nooo, noone is allowed get past you!
I usually bodycheck these assholes as I'm fed up with these idiots that think they own the road. Keep your head on a swivel or fucking take your stupid earbuds out!