Red Noise

Red noise is the same as brown noise — the two names refer to the same audio signal. The name "brown noise" comes from botanist Robert Brown and his discovery of Brownian motion (the random movement of particles), while "red noise" is a reference to the red end of the visible light spectrum, where low frequencies sit.

Both names describe noise where power decreases at 6dB per octave as frequency increases, creating that deep, bass-heavy rumble. The "brown noise" name has become dominant in popular culture following the ADHD focus trend, but "red noise" is the technically correct audio engineering term.