Although I always have my MP3 player set so that I can hear background noise and I've found just the right headphones so that this works, when drivers get a bit closer and notice the brightly coloured wires, people often assume that I'm deaf to their shouts.
Yesterday morning on the way to work, I had the usual moron tailgating me through the narrow bits and revving her engine because she couldn't get past. I just ignored her and carried on. When we stopped at the lights, she opened her window and shouted, "Don't ride in the middle of the road - read the fucking highway code!"
Although I'd heard her quite clearly, I made sure that whilst ignoring her, I visibly tapped my foot and nodded my head to the rather splendid bluegrass album I was listening to.
It's times like this when I regret that having a rear view mirror would spoil my fixie cool