Read this to yourself, read it silently.
Don't move your lips, don't make a sound. Listen to yourself. Listen without hearing anything. What a wonderfully weird thing, huh?
NOW MAKE THIS PART LOUD!
SCREAM IT IN YOUR MIND!
DROWN EVERYTHING OUT!
Now make this as a whisper, a tiny, little whisper..
Now with your best crotchety old-man voice: 'hey there, sonny, does your town has a post office?' 
Awesome! Who was that? Who's voice was that? Sure it wasn't yours!

How do you do that?!
How?!
Must be magic.