Yesterday I had the privilege of appearing on the WNYC radio show Soundcheck to talk about the origins of booing. The news hook was a recent Metropolitan Opera production of La Sonnambula that got booed by the audience thanks to its avant-garde staging. Wall Street Journal drama critic Terry Teachout discussed the booing incident, and I was there to provide some historical and linguistic context.
Though boisterous expressions of disapproval at public performances go at least as far back as ancient Greece, the English word boo (an interjection, a noun, and a verb) is of relatively recent vintage. Like other onomatopoetic words, boo is a bit hard to trace, since it may have existed in oral use long before someone thought to write it down.
Besides the boo of the crowd, we also know boo as an exclamation to surprise or frighten someone, and that use predates the expression of contempt or scorn. Early versions of the surprising noise were spelled bo or boh, which the Oxford English Dictionary considers "a combination of consonant and vowel especially fitted to produce a loud and startling sound." Latin and Greek have similar words starting with bo- that mean "to cry aloud, roar, shout." Boo began to be used as a variant of bo by the early 18th century, at least in Scotland; a source from 1718 says "Boo is a word used in the North of Scotland to frighten crying Children."
The frightening boo is short and staccato, but a lengthened version of the same sound was used as an imitation of oxen or cattle, much like moo. When boo began to be used contemptuously in the 19th century, it thus evoked both the cattle-like sound and the frightening sound. In Maria Edgeworth's novel Castle Rackrent, first published in 1800, boo appears as an Irish interjection that Edgeworth glosses in a footnote as "an exclamation equivalent to Pshaw! or Nonsense." From these origins, boo became a general noise of disdain from disappointed audiences.
The modern practice of booing may have originated at England's prestigious public school, Eton College. Rebellious students at Eton in the early 19th century were notorious for rowdily shouting down their elders with cries of "Boo!" A diary of an Eton boy published in the school magazine The Kaleidoscope in 1833 shows that the word had already turned into a verb: he describes an address given by a headmaster where "the whole school raised a yell, booing, hissing, and scraping feet." Later in the diary he recalls coming to school late and being "boo'd, laughed at, [and] shinned in getting a seat."
Other onomatopoetic words did the trick before boo came on the scene. Hoot has a much longer history; the OED traces derisive "hooting" all the way back to the 13th century, with hoot imitative of the sound of an owl as it still is today. Other English words representing the sound of a jeer have similarly incoroporated the long "u" vowel, such as pooh. (In Hamlet, Polonius says to Ophelia, "Affection! pooh! you speak like a green girl.") Yet another derisive interjection, popular in the 17th century, was mew — with cats rather than oxen or owls as the animalistic model.
The imitation of unpleasant feline noises is also the source for catcall. A catcall was originally a kind of shrill whistle that one would blow on to register disapproval at a theatrical performance. In a 1660 entry in his famous diary, Samuel Pepys recounts going to a shopkeeper and buying a catcall, which cost him two groats (eight pence). Catcall then came to describe the sound of such a whistle imitated by the voice.
A more modern innovation in derisive jeering is the raspberry, a sound made by sticking out one's tongue between one's lips and blowing. (In phonetics that would be called a "linguolabial trill.") The term raspberry, first recorded in 1890, originates in rhyming slang: it's short for raspberry tart, which in turn rhymes with fart, which the sound was supposed to imitate. Since the early 20th century, the sound has also been known as the Bronx cheer, though it's unclear whether that originally referred to the noises made by jeering Yankee fans or the borough's difficult-to-please vaudeville audiences.