You can find one or more right here on instructables:https://www.instructables.com/id/Talking-Animatronic-Robot-Head/
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Woot.com once sold a clamp on amp that was a pair of lips the moved. It was for amping a cell phone for group listening. The lips were balanced so that it took very little power to move them and there was a magnet and coil that moved them time with the sound. I suggest trying a solenoid and power amp.
https://www.instructables.com/answers/Hey-any-ideas-how-I-can-make-a-robot-mouth-that-mo/Anything there that helps ?