doesnt affect me (my observational drawing training as an artist has made me pretty good at focussing on a visual 'target' and the connected physical action to the exclusion of all else) but good advice i think is the tip my dad gave me when i was learning to drive
talk to yourself in your head as if you were commentating on your own actions for TV or radio - focuses your thoughts on what you are doing and should help to block out external distractions
either that or some big f - erm - jolly large ear defenders !
slainte
rob