I haven't seen this yet, but I'll make a point of seeing it now.
From what I got from the trailer and the comments here, I think the ear buds he wears are necessary to make his invisible affliction visible. Of course it would be more accurate if he wore Peltor muffs throughout the movie instead (which might make wearing Peltor muffs cool!), but that would not fit the story of him being focused on the beat of the music (or maybe they should have given him pulsatile tinnitus). But I'm guessing that the movie has a music soundtrack that pumps up the audience just as it pumps up the protagonist. I mean, who'd want to see a movie if they had to listen to pulsatile tinnitus for two hours?
I think this movie should have a public service announcement at the end where the actor who plays Baby tells the audience the truth about tinnitus. I'm assuming there isn't one because no one on this thread mentioned any. What a missed opportunity to raise awareness and educate people!!