When I was eight years old, I got a dummy for Christmas and started teaching myself. I got books and records and sat in front of the bathroom mirror, practising. I did my first show in the third grade and just kept going there was no reason to quit.
– Jeff Dunham
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.