Noise (spectral phenomenon)

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Noise refers to many types of random, troublesome, problematic, or unwanted signals.

Acoustic noise may mar aesthetic experience, such as attending a concert hall. It may also be a medical issue inherent in the biology of hearing.

In technology, noise is unwanted signals in a device or apparatus, commonly of an electrical nature. The nature of noise is much studied in mathematics and is a prominent topic in statistics.

This article provides a survey of specific topics linked to their primary articles.

Acoustic noise[edit]

In transportation[edit]

Other acoustic noise[edit]

Noise in biology[edit]

Noise in computer graphics[edit]

Noise in computer graphics refers to various pseudo-random functions used to create textures, including:

  • Gradient noise, created by interpolation of a lattice of pseudorandom gradients
  • Simplex noise, a method for constructing an n-dimensional noise function comparable to Perlin noise
  • Simulation noise, a function that creates a divergence-free field
  • Value noise, created by interpolation of a lattice of pseudorandom values; differs from gradient noise
  • Wavelet noise, an alternative to Perlin noise which reduces problems of aliasing and detail loss
  • Worley noise, a noise function introduced by Steven Worley in 1996

Noise in electronics and radio[edit]

Noise in mathematics[edit]

  • Any one of many statistical types or colors of noise, such as
    • White noise, which has constant power spectral density
    • Gaussian noise, with a probability density function equal to that of the normal distribution
    • Pink noise, with spectral density inversely proportional to frequency
    • Brownian noise or "brown" noise, with spectral density inversely proportional to the square of frequency
  • Pseudorandom noise, in cryptography, artificial signal that can pass for random
  • Statistical noise, a colloquialism for recognized amounts of unexplained variation in a sample
  • Shot noise, noise which can be modeled by a Poisson process
  • Noise-based logic, where logic values are different stochastic processes
  • Noise print, a statistical signature of ambient noise, used in its suppression

Other types of noise[edit]

Measures of noise intensity[edit]

See also[edit]