There's a rainbow of noise out there. We've brought them all together here, to create a scientifically accurate audio rainbow.
To hear the stories of the different colours of noise and the lives affected by them, click on the bands below - the black band will mute the noises, if you need a break...
This rainbow is part of the PRX STEM Story Project, made possible by the Alfred P. Sloan Foundation.
-
Brown
Also known as Brownian noise. Used in climatology to describe climate regime shifts. Sounds like a low roar, like a waterfall. Not connected to the mythical brown note, the frequency that supposedly, when played loudly, loosens human bowels.
-
Pink
The power of the different frequencies falls away logarithmically in the pink noise spectrum. Means pink noise covers similar frequencies to human hearing. Used to test speakers, and aid sleep.
-
White
Often referred to as static. Contains a broad range of frequencies, which means it can cut through background noise. For this reason, it is sometimes used in emergency vehicles' sirens.
-
Purple
Used in the treatment of tinnitus, as its high frequencies often drown out the similar ringing heard by many tinnitus sufferers.
-
Blue
Inverse of pink – increasing power with increasing frequency, so a high hissy sound. Retinal cells in the eye are arranged in a blue-noise pattern.
-
Black
Black noise has several different definitions. To some, it is pure silence. To others it is negative noise – the output of an active noise control system that cancels out existing noise.