When I was a kid, I was always sending off box tops for little toys. One of them was a guitar pick-looking thing that went under your tongue and was supposed to enable you to throw your voice. I could never make it work.
Actually, “throwing one’s voice” is only an illusion. What you’re really doing is using a fake voice and misdirecting the audience’s attention to the dummy’s mouth and expressions. I was the dummy for believing 10 box tops would make me a ventriloquist!