The Vocoder: The Incredible History of a Great Invention

This replica shows just what the talking device is able to do…

Dudley's presentation on the Voder, a further development on the vocoder, created quite the stir at the 1939 New York's World Fair. The principle was similar. Only the input signal was not the human voice. Instead, a woman named Helen Harper operated a keyboard and pedals, like an organ, which the voder then converted into an artificial human voice.

What the auditorium in New York could hear, for example, was the phrase "Good afternoon, Radio Science." According to the New York Times, however, the quality was so astoundingly poor that it sounded like something otherworldly had spoken underwater.

Naturally, the military (pictured here: General Dwight D. Eisenhower was also keen to hear about it. With the vocoder as their basis, Bell Labs developed the SIGSALY system, a hefty machine weighing over 50 tonnes for speech encryption which politicians and the Allied militaries could use to communicate across the Atlantic. It encrypted the voices of the speakers at one end of the line every 20 milliseconds—50 times per second—and sent them across the Atlantic. The voices were only decrypted and synthetically reconstructed for the listener once they reached the other end.

In the entertainment industry. Werner Meyer-Eppler, founder of the Studio for Electronic Music of the West German Radio, had already investigated synthetic language in 1948 in his book Electronic Sound Creation (Elektronische Klangerzeugung).

From 1956 to 1959 a vocoder was integrated in the Siemens Studio, now a Deutsches Museum exhibit, which was used among other things to record the legendary countdown of cult sci-fi series Orion Space Patrol (Raumpatrouille Orion) in the 1960s.

For background, according to lore, co-author Author C. Clarke happened to attend a synth vocoder presentation at Bell Labs and was deeply impressed when the IBM 704 sang the song Daisy Bell.

The world of distorted and alien voices became even more popular from the 1970s. As the greatest pioneers of electronic music, Kraftwerk used the vocoder more and more often, such as in their epochal album Autobahn in 1974 where they formed their unemotional, cold, industrial-electro sound that was typical for them from this point onward.

It was Afrika Bambaataa and his hit Planet Rock that introduced the vocoder to the world of hip-hop in the early '80s. In the late 1990s, the Brit rockers of Radiohead played a computer-generated voice in Fitter Happier. And the intro to 24k Magic by Bruno Mars by Mr. Talkbox also featured a vocoder.

It had long been assumed that Cher also used a vocoder in her worldwide hit Believe in 1997. It only emerged later that Auto-Tune, the very recently developed and commercially released audio processor, produced the distorted voice effect.

From its military applications to its use in science-fiction films through to pop, rock, and hip-hop, Homer Dudley could never have imagined what his invention would eventually be used for.