Ring modulation was popular in early electronic music, and one of the first examples of its use was in the Melochord, an instrument built by the electronic music pioneer, Harald Bode, in 1947. But ring modulation really came of age as a special effect in science fiction film and television.
In 1956, Louis and Bebe Barron were commissioned to do twenty minutes of sound effects for the Sci-Fi movie Forbidden Planet. After creating some initial samples, the producers were sufficiently impressed to ask the husband and wife team to compose the entire score. This was one of the first electronic scores for a major film, and made heavy use of ring modulators that were built by Louis and Bebe. They treated each ring modulator as a different ‘actor,’ with a unique voice and behavior. As they explained on the sleeve notes for the soundtrack album, “we created individual cybernetics circuits for particular themes and leit motifs, rather than using standard sound generators. Actually, each circuit has a characteristic activity pattern as well as a ‘voice’.”
Ring modulation was also used heavily by the BBC Radiophonic Workshop, a sound effect unit of the BBC well-known for innovations in sound synthesis and effects. For the voice of the Daleks, first used in 1963, Brian Hodgson applied a 30 Hz modulation, among other effects, to give a harsh buzzing sound to the voices. Ring modulation has been applied to almost every Dalek voice since, and a Moog ring modulator has also been used to generate as a special effect on the voices of another Doctor Who villain, the Cybermen.
The ring modulator has become synonymous with sci-fi sound effects. Its easily recognizable in classic productions, such as The Outer Limits and The Hitchhiker’s Guide to the Galaxy. Today, it’s an essential sound effect in television, film and game audio production.