Noise refers to a random, non-periodic signal that covers a broad range of frequencies. Noise generators are commonly used as sound sources or modulators within a modular synthesizer, offering a variety of applications in sound design and synthesis.
There are several types of noise commonly used in modular synthesizers:
- White noise: Contains equal power across all frequencies, resulting in a bright, dense sound. White noise is often used for creating percussive sounds, such as hi-hats and snare drums, as well as a modulator for generating random variations in other parameters.
- Pink noise: Has equal power per octave, meaning that the power density decreases as frequency increases. This results in a more balanced and smoother sound compared to white noise. Pink noise is often used for creating more natural-sounding textures and as a modulator for more musically relevant random variations.
- Brownian or Brown noise: Has a power density that decreases at a rate of 6 dB per octave, resulting in a darker, warmer sound with more emphasis on lower frequencies. Brownian noise can be used for creating deeper, more bass-heavy sounds or as a modulator for slower, smoother random variations.
- Blue noise: Has a power density that increases at a rate of 3 dB per octave, resulting in a brighter, more high-frequency focused sound compared to white noise. Blue noise can be used for creating sharp, bright sounds or as a modulator for more high-frequency focused random variations.
Noise sources in a modular synthesizer can be used for various purposes, such as creating percussive and atmospheric sounds, adding texture and character to other audio signals, or serving as a random voltage source for modulating parameters like pitch, filter cutoff, or amplitude.