When one thinks of electronically altering the human voice, one usually thinks of the Vocoder, which came to prominence in late '70s/early '80s disco, funk, and New Wave records, Zapp's "More Bounce To The Ounce" and Laurie Anderson's "O Superman" being two classic examples. Incredibly, a precurser to the Vocoder was invented back in the mid-Thirties. The Sonovox used small speakers attached to the singer's throat that were patched through music instruments - horns, guitars, etc. The singer mouthed the words of a song, and by changing the shape of the mouth and position of the tongue, changed the sound of the instrument. It created a pretty weird robot-voice-like effect.
Musicians in the '30s and '40s didn't really know what to do with it, so it was usually used on children's records or, as on The Who's "Sell Out" album, radio ads. But, amazingly, one Big Band leader used it to mind-boggling effect:
Kay Kyser & his Orchestra: from "You'll Find Out"
This performance is from a 1940 film called "You'll Find Out" featuring the dream cast of Boris, Bela, and Peter Lorre. But the Sonovox was practically the star of the film, providing music, wind and ghost sound effects.
KiddieRecords.com has posted several vintage children's records that used the sonovox - look for Chug Chug in Lollypop Town, Little People's Band in Forestland, and Whizzer the Talking Airplane. Although you may not want to play them for your kids. As Ford from KiddieRecords says, "The creepy sonovox vocal effects may be a bit much for small fry, so proceed with caution."