I'm probably missing the whole point of the conversation, but to add on:
So many on-air people have speech impediments. Many are able to "hide" them or use them to an advantage on air, while others simply just act normally.
I, for one, had a horrible problem with stuttering. It plagued me until college when I finally got into radio. I focused on what I was going to say, and it came out smooth as silk 95% of the time! Combine that with a rich, deep smoker's voice and you too can sound good! (except for right now as I'm suffering from strep throat and going through nicotine withdrawals ;D)
Basically, you would be surprised that the dude (or dudette) you listen to on the air looks and sounds totally different than they do on the magical world of radio.
Radio-X