White noise

In signal processing, white noise is a random signal with a constant power spectral density. The term is used, with this or similar meanings, in many scientific and technical disciplines, including physics, acoustic engineering, telecommunications, statistical forecasting, and many more. White noise refers to a statistical model for signals and signal sources, rather than to any specific signal.

In discrete time, white noise is a discrete signal whose samples are regarded as a sequence of serially uncorrelated random variables with zero mean and finite variance; a single realization of white noise is a random shock. Depending on the context, one may also require that the samples be independent and have the same probability distribution (in other words i.i.d is a simplest representative of the white noise). In particular, if each sample has a normal distribution with zero mean, the signal is said to be Gaussian white noise.

The samples of a white noise signal may be sequential in time, or arranged along one or more spatial dimensions. In digital image processing, the pixels of a white noise image are typically arranged in a rectangular grid, and are assumed to be independent random variables with uniform probability distribution over some interval. The concept can be defined also for signals spread over more complicated domains, such as a sphere or a torus.

White noise (slang)

The term white noise, the 'sh' noise produced by a signal containing all audible frequencies of vibration, is sometimes used as slang (or a neologism) to describe a meaningless commotion or chatter that masks or obliterates underlying information.

The information itself may have characteristics that achieve this effect without the need to introducing a masking layer. A common example of this usage is a politician including more information than needed to mask a point he doesn't want noticed.

In music the term is used for music that is discordant with no melody; disagreeable, harsh or dissonant.

"White noise" in the media

On the January 11, 2005 broadcast of ABC's Good Morning America, Claire Shipman claimed "the political rhetoric on Social Security is white noise" to most Americans.

The novel White Noise by Don DeLillo explores several themes that emerged during the mid-to-late twentieth century. The title is a metaphor pointing to the confluence of all the symptoms of postmodern culture that in their coming-together make it very difficult for an individual to actualize his or her ideas and personality.

White noise (disambiguation)

White noise is a signal or sound with a flat frequency spectrum.

White noise may also refer to:

In music