Noise is any type 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
In transportation Aircraft noise Jet noise, caused by high-velocity jets and turbulent eddies Noise and vibration on maritime vessels Noise, vibration, and harshness, quality criteria for vehicles Traffic noise, including roadway noise and train noise
Other acoustic noise Artificial noise, in spectator sports Background noise, in acoustics, any sound other than the monitored one Comfort noise, used in telecommunications to fill silent gaps Grey noise, random noise with a psychoacoustic adjusted spectrum Industrial noise, relevant to hearing damage and industrial hygiene Noise pollution, that affects negatively the quality of life
Noise in biology Cellular noise, in biology, random variability between cells Developmental noise, variations among living beings with the same genome Neuronal noise, in neuroscience Synaptic noise, in neuroscience Transcriptional noise, in biochemistry, errors in genetic transcription
Noise in computer graphics 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 Perlin noise, a type of gradient noise developed in 1983 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 Noise (signal processing), various types of interference Noise (electronics), related to electronic circuitry Ground noise, appearing at the ground terminal of audio equipment Image noise, related to digital photography Noise (radio), interference related to radio signals Atmospheric noise, radio noise caused by lightning Cosmic noise, radio noise from outside the Earth's atmosphere Noise (video), "snow" on video or television pictures
Noise in mathematics 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 Electrochemical noise, electrical fluctuations in electrolysis, corrosion, etc. Phonon noise, in materials science Seismic noise, random tremors of the ground
Measures of noise intensity Noise figure, the ratio of the output noise power to attributable thermal noise Ambient noise level, the background sound pressure level at a given location Noise power, with several related meanings Noise spectral density, No measured in Watt/Hertz Noise temperature, temperature that would produce equivalent semiconductor noise
See also Noise (disambiguation)
