How do you make stop motion figures "talk"?

Question

in the series robot chicken it actually looks like the little dolls are talking, how do you do that?

Answer 1

What they do on Robot Chicken is use replacement mouths. They have multiple paper mouths in different shapes which represent certain shapes mouths make when we speak. They pre-record the audio for the show then listen and break down the recorded audio so they can work out what mouth shapes should be used and how many frames they should last before changing it for a different mouth shape. It's essentially the same process as lip syncing for hand drawn animation, but instead of drawing a different mouth shape on a character, they're sticking on a previously made paper/cardboard mouth.