"sound made up of a random mixture of frequencies and intensities," by 1970, from white (adj.) + noise (n.).
Entries linking to white noise
white adj.
Old English hwit "bright, radiant; clear, fair," also as a noun (see separate entry), from Proto-Germanic *hweit- (source also of Old Saxon and Old Frisian hwit, Old Norse hvitr, Dutch wit, Old High German hwiz, German weiß, Gothic hveits), from PIE *kweid-o-, suffixed form of root *kweit- "white; to shine" (source also of Sanskrit svetah "white;" Old Church Slavonic sviteti "to shine," svetu "light;" Lithuanian šviesti "to shine," švaityti "to brighten").
As a surname, originally with reference to fair hair or complexion, it is one of the oldest in English, being well-established before the Conquest. Meaning "morally pure" was in Old English. Association with royalist causes is late 18c. Slang sense of "honorable, fair" is 1877, American English; in Middle English it meant "gracious, friendly, favorable." The racial sense "of those races (chiefly European or of European extraction) characterized by light complexion" is recorded from c. 1600; meaning "characteristic of or pertaining to white people" is from 1852, American English. White supremacy attested from 1868, American English [John H. Van Evrie, M.D., "White Supremacy and Negro Subordination," New York, 1868]; white flight is from 1966, American English.
White way "brightly illuminated street in a big city" is from 1908. White flag of truce or surrender is from c. 1600. White lie is attested from 1741. White Christmas is attested from 1847. White House as the name of the U.S. presidential residence is recorded from 1811. White water "river rapids" is recorded from 1580s. White Russian "language of Byelorussia" is recorded from 1850; the mixed drink is from c. 1978. Astronomical white dwarf is from 1924. White witch, one who used the power for good, is from 1620s.
noise n.
c. 1200, "sound of a musical instrument;" mid-13c., "loud speech, outcry, clamor, shouting;" c. 1300, "a sound of any kind from any source," especially a loud and disagreeable sound, from Old French noise "din, disturbance, uproar, brawl" (11c., in modern French only in phrase chercher noise "to pick a quarrel"), also "rumor, report, news," a word of uncertain origin, replacing Replaced native gedyn (see din).
According to some, it is from Latin nausea "disgust, annoyance, discomfort," literally "seasickness" (see nausea). According to others, it is from Latin noxia "hurting, injury, damage." OED considers that "the sense of the word is against both suggestions," but nausea could have developed a sense in Vulgar Latin of "unpleasant situation, noise, quarrel" (compare Old Provençal nauza "noise, quarrel"). Confusion with annoy, noisome, and other similar words seems to have occurred.
From c. 1300 as "a disturbance; report, rumor, scandal." In Middle English sometimes also "a pleasant sound." In 16c.-17c. "a band or company of musicians." Noises off, as a stage instruction in theater, "sound effects, usually loud and confused, made off stage but to be heard by the audience as part of the play," is by 1908.