The → random → fluctuations
that are always associated with a measurement that is repeated many times over.
Any unwanted disturbance, random or → systematic,
which contaminates the → signal from an object under study.
More specifically:
Electronics: An undesired signal within the useful frequency band.
Acoustics: Any extraneous sound tending to interfere with the perception of
wanted sound.
See also:
→ atmospheric noise,
→ background noise,
→ cosmic radio noise,
→ dark current noise,
→ Galactic radio noise,
→ Johnson-Nyquist noise,
→ noise source,
→ noise temperature,
→ noise voltage,
→ noise-equivalent power,
→ photon noise,
→ quantum noise,
→ radio noise,
→ random noise,
→ readout noise,
→ receiver noise,
→ Schottky noise,
→ shot noise,
→ signal-to-noise ratio,
→ speckle noise,
→ stationary noise,
→ system noise,
→ thermal noise,
→ white noise.
Etymology (EN): Noise, of obscure origin; it has been related to
O.Fr. noise “uproar, brawl,” apparently from L. nausea
“disgust, annoyance,” literally “seasickness.” Alternatively the O.Fr. word is traced to
L. noxia “hurting, injury, damage.”
Etymology (PE): Nufé “noise,” related to Mod.Pers. noyidan “to cry loud, lament,”
navidan, nâvidan “to lament,” noyé, nôyah “plaint, mown,”
navâ “sound, song,”
(with prefix *uz-) zenudan, zenav-, zonudan “to wail,”
Ossetic niwyn/newun “to howl,”
O.Khotanese nuva- “to make a noise,”
Yaqnâvi nuyok “crying, howling,” novva “sound,”
Shahmirzâdi nâv- “to cry;
cf. Skt. nav- “to sound loudly, roar,” náva- “show of joy or triumph;”
L. nuntius “messenger,” adnuntiare “to annoince;”
Tocharian AB nu- “to roar, PIE *neu- “to shout”.
