In science, brown noise takes its name from Brownian motion, a sort-of random, foot-stepping pattern of motion. The graphic representation of the sound signal mimics a Brownian pattern. It decreases in power by 6 dB per octave and, when heard, has a "damped" or "soft" quality compared to white and pink noise. See also violet or purple noise, which is a 6 dB increase per octave.

So-called "brown noise" was featured in an episode of South Park (Worldwide Recorder Concert) as a sound that caused people to lose their bowels uncontrollably, though the sound in the show was a low tone, not noise. In reality, very loud infrasonic tones are rumored to have this effect, see brown note.