What is Audio Rate Modulation?

Audio Rate Modulation is a synthesis technique in which one audio signal modulates another at frequencies within the audible range. It is known for creating complex, harmonically rich, and often aggressive sounds.

The process typically involves using an oscillator as a modulator that operates at audio frequencies, rather than low-frequency modulation like an LFO. This causes rapid changes in parameters such as pitch, amplitude, or filter cutoff, producing new harmonics and intricate tonal variations.

Audio Rate Modulation emphasizes timbral complexity, as the interaction between signals can generate both harmonic and inharmonic content depending on the relationship between frequencies.

It is commonly used in techniques like frequency modulation (FM), amplitude modulation (AM), and ring modulation, where it contributes to evolving, metallic, or textured sounds.

Today, Audio Rate Modulation is widely used in electronic music and advanced sound design, valued for its ability to create detailed, dynamic, and highly expressive tones.