This video is an amazing historical demo, from 1939, of the VODER – considered by some to be the first attempt to synthesise human speech by breaking it down into its component sounds and then reproducing the sound patterns electronically.
Per Wendy Carlos:
Homer Dudley….invented the VODER (Voice Operating DEmonstratoR), an electronic speaking instrument, which was unveiled (and demonstrated hourly) at the New York World’s Fair 1939-40.
Inside the tall rack of sturdy electronic gear was a pitch controlled reedy oscillator, a white-noise source, and ten bandpass resonant filters. For a Voder to “speak” a talented, diligently trained operator “performed” at a special console connected to the rack, using touch-sensitive keys and a foot-pedal. These controlled the electronic generating components. The results, while far from perfect (it was damn difficult to operate!), were still entertaining and instructive of the principles involved.