Looking at screens to get key information distracts me from my surroundings and seems archaic.
My wife is a sound designer who has opened my eyes to the importance of sounds both in film and in the world. It's not that I was unaware of sounds, but I didn't realize how important they are to centering me in this world and the made up worlds of films and games. Try watching a scary movie with the sound turned off, it turns into a comedy.
I think its unexplored territory that has huge potential to impact the way we interact with the real world, even more so then Glass or Hololens.
When I listen to music as I walk down the street I change, my mood, my posture and the way I look at the world. The music augments the reality around me in a way that visual UX never can because it's a lens between my eyes and the world.