Brown Noise: Deep, Low Frequencies for Rest and Focus

Brown noise — sometimes called Brownian or red noise — concentrates its energy heavily in the lowest frequencies, producing a deep, rumbling sound. It's named after Robert Brown and the mathematical pattern of Brownian motion, not the color. If you've ever found comfort in the low hum of a distant thunderstorm, the drone of a jet engine at cruising altitude, or the deep roar of a waterfall, you've experienced something close to brown noise.

Where white noise distributes energy equally across all frequencies and pink noise favors lower tones gently, brown noise drops off sharply as frequency increases. The result is a rich, bass-heavy blanket of sound that many listeners find uniquely effective for deep concentration and sleep. It has become especially popular among people with ADHD and those who find higher-pitched noise colors too stimulating or harsh.

Explore our guides below to understand the science behind brown noise, how it compares to white and pink noise, and how to use it effectively for sleep, focus, and relaxation. Every article is backed by published research and updated regularly.

Last updated March 2026