The premise is an outrageously literal joke about a woman whose vagina develops a voice and ambitions of its own. Chatterbox! stretches that idea into a show business comedy, using songs, professional jealousy and public embarrassment to keep an impossible situation moving. The interesting tension is between the heroine's control of her life and the demands of a newly vocal part of her body. Its sexual humor belongs to a particular exploitation tradition, so the question is less whether the premise is tasteful than how inventively the film develops it.