In common use, the word noise means any unwanted sound.
In physics and analog electronics, noise is a mostly unwanted random addition to a signal; it is called noise as a generalisation of the acoustic noise ("static") heard when listening to a weak radio transmission with significant electrical noise. Signal noise is heard as acoustic noise if the signal is converted into sound (e.g., played through a loudspeaker); it manifests as "snow" on a television or video image. High noise levels can block, distort, change or interfere with the meaning of a message in human, animal and electronic communication.
In signal processing or computing it can be considered random unwanted data without meaning; that is, data that is not being used to transmit a signal, but is simply produced as an unwanted by-product of other activities. "Signal-to-noise ratio" is sometimes used to refer to the ratio of useful to irrelevant information in an exchange.
In biology, many different forms of cellular noise exist, where a measurement displays substantial variance around its mean: for example, transcriptional noise describes the variability in gene activity between cells in a population.
In many cases, the special case of thermal noise arises, which sets a fundamental lower limit to what can be measured or signaled and is related to basic physical processes described by thermodynamics, some of which are expressible by simple formulae.
In some fields, noise means unwanted information or data that is not relevant to the hypothesis or theory being investigated or tested.
Other articles related to "noise":
... This article is about NOiSE the manga ... For other uses, see Noise (disambiguation) ... NOiSE Musubi on top of early silicon creatures NOiSE (ノイズ) Genre Cyberpunk Manga Written by Tsutomu Nihei Published by Kodansha English publisher Tokyopop Demographic Seinen Magazine ...
... Historically noise violations were the responsibility of the party making the noise ... Besides being difficult to enforce, music aficionados claim that noise ordinances threaten the city's music culture ...
... Main article Cellular noise The activity and regulation of our genes are also subject to noise ... Transcriptional noise refers to the variability in gene activity between cells in genetically identical populations (even identical twins are non-identical) ... Noise in gene activity has tremendous consequences on cell behaviour, and must be mitigated or integrated ...
... partly by the signal processing used and partly by the level of background noise ... Ambient noise is that part of the received noise that is independent of the source, receiver and platform characteristics ... This it excludes reverberation and towing noise for example ...
... Noise FM is an Australian radio station that operates on the FM band in Ballarat, Victoria ... Noise FM's on air format is a fresh new mix of Alternative, Rock, Pop, Hip Hop, R B, Rap and Dance ... Noise FM sold their Victorian Low Power FM licences to Christian based broadcast group Lifeinfo Media, which is an Australian based not for profit service ...
Famous quotes containing the word noise:
“And its noise as the noise in a dream; and its depth as the roots
of the sea:”
—A.C. (Algernon Charles)
“The noise of battle hurtled in the air,
Horses did neigh, and dying men did groan,
And ghosts did shriek and squeal about the streets.”
—William Shakespeare (15641616)
“I will not by the noise of bloody wars and the dethroning of kings advance you to glory: but by the gentle ways of peace and love.”
—Thomas Traherne (16361674)