I want to let my friend Buster know that I would like to have dinner with him tonight. Does Buster work at home? Then how likely is he to have his cell phone on? Is he one of those people who only turns on his cell when he's in his car? I hate that.
But the mechanics of learning to 'throw your voice' are pretty simple. Anyone with a tongue an upper palate teeth and a normal speaking voice can learn ventriloquism.