Frequency Modulation (FM) Synthesis

The first commercial digital sound synthesis method was frequency modulation (FM) synthesis [37,40,38], invented by John Chowning, the founding director of CCRMA. FM synthesis was discovered and initially developed in the 1970s [37]. The technology was commercialized by Yamaha Corporation, resulting in the DX-7 synthesizer (1983), which was the first commercial digital synthesizer, and the OPL chipset, initially in the SoundBlaster PC sound card, and later a standard chipset required for ``SoundBlaster compatibility'' in computer multimedia support. The original pioneer patent expired in 1996, but additional patents were filed later. It is said that this technology lives on in cell-phone ring-tone synthesis.

As developed more fully in [248], the formula for elementary FM synthesis is given by

where

specify the carrier sinusoid

specify the modulator sinusoid

Since instantaneous frequency is simply the time-derivative of instantaneous phase, FM can also be regarded as phase modulation

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Subsections

• FM Harmonic Amplitudes
• FM Brass
• FM Voice
  • Further Reading about FM Synthesis

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Next: FM Harmonic Amplitudes (Bessel Functions)

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About the Author: Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.