Incredible Sonovox - Kay Kyser - 1940 film "You'll Find Out"

Amazing device that gives voice to musical instruments. The Sonovox consists of one or two louspeakers placed on the throat that play the source sound. The performer whispers the words while the speakers stand in for the voice box. Used for the talking train in Disney's Dumbo, uncountable radio promos, a tube-in-the-mouth version "Talk Box" was used by Frampton to make his guitar sing, and all-electronic "Vocoder" versions are still used in current pop music. LINK: Youtube