The Vocoder: From Speech-Scrambling To Robot Rock

If you've listened to pop music in the past 40 years, you've probably heard more than a few songs with a robotic sound. That's thanks to the vocoder, a device invented by Bell Labs, the research division of AT&T. Though the vocoder has found its way into music, the machine was never intended for that function. Rather, it was developed to decrease the cost of long-distance calls and has taken on numerous other uses since.

Music journalist Dave Tompkins has written a book about the vocoder and its unlikely history. It's called How to Wreck a Nice Beach: The Vocoder From World War II to Hip-Hop.

Tompkins says the machine played a significant role in World War II. After the U.S. government discovered that Winston Churchill's conversations with Franklin D. Roosevelt were being intercepted and deciphered by the Germans, it decided to invest in speech-encoding technology. So the National Defense Research Committee commissioned Bell Labs in 1942 to develop a machine -- and Bell Labs delivered.

The vocoder wasn't without its flaws. Intelligibility of speech sometimes proved a problem, but Tompkins says pitch control was a bigger concern.

"They didn't mind world leaders sounding like robots, just as long as they didn't sound like chipmunks," he says. "Eisenhower did not want to sound like a chipmunk."

From Military Base To Music Studio

The vocoder experienced a major transition from military device to musical effect when Wendy Carlos used it on the soundtrack for 1971's A Clockwork Orange. Carlos did a vocoder interpretation of the fourth movement of Beethoven's Ninth Symphony, which Tompkins says exposed the vocoder in unprecedented ways.

"Essentially, that introduced the vocoder to its first major audience," he says. "A lot people had no idea what it was. As the vocoder evolved, they knew the voice but had no idea where it came from."

After A Clockwork Orange, though it was still an expensive technology, the vocoder saw wider use in music studios. The German band Kraftwerk was one of the first musicians to employ it in its work. It fit perfectly, Tompkins says, because the band's work was primarily electronic.

Later, in the 1980s, the vocoder became the voice of electro-funk hip-hop. Michael Jonzun recorded what is believed to be the first hip-hop vocoder album, Lost in Space, in 1983. The futuristic sounds complemented the synthesizer, which became widely heard in music from that decade.

The vocoder is less prevalent in today's popular music, but its legacy lives on. Its successor is Auto-Tune, the pitch-correcting software prominent in popular music today.

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