Main Page | See live article | Alphabetical index 1/f noise is a signal or process with a frequency spectrum such that the spectral energy density is proportional to the reciprocal of the frequency. 1/f noise is also called pink noise or flicker noise. In particular, there is equal energy in all octaves. In terms of power at a constant bandwidth, 1/f noise falls off at -3dB per octave. 1/f noise is found in a wide variety of physical phenomena. Examples include electronic devices, financial markets, astronomy, and human coordination. The human auditory system, which uses a roughly logarithmic concept of frequency, perceives equal magnitude at all frequencies. Graphic equalizers also divide signals into bands logarithmically and report power by octaves; audio engineers put pink noise through a system to test whether it has a flat frequency response in the useful spectrum. See also White noise Statistics Audio signal processing Self-organised criticality Fractal External link http://linkage.rockefeller.edu/wli/1fnoise/ This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.