From Wikipedia, the free encyclopedia.
White noise is a signal or process with a flat frequency spectrum. In other words, there is equal energy in a given bandwidth at any centre frequency. In time domain, the magnitude of a white noise process has normal distribution.
In digital signal processing, almost all types of noise are often approximated with white noise since it has several useful statistical properties. For example, it is statistically uncorrelated in time with any other signal, including itself.
In practical applications few signals are exactly white noise, or even close to white noise. However, signals such as gunshot noise and thermal noise have a close to flat spectrum.
A closely related concept is pink noise which is a sound that is perceptually white noise. That is, the human auditory system perceives equal magnitude on all frequencies.
One use for white noise is in the field of architectural acoustics. Here in order to submerge distracting, undesirable noises (for example conversations, etc.,) in interior spaces, a constant level of sound at a desired decibel level is generated and provided as a background. In this context it is also referred to as grey noise.
White noise has also been used in much electronic music.
See also: Statistics
White Noise is a 1985 novel by Don DeLillo.
