The bullroarer, rhombus, or turndun, is an ancient ritual musical instrument and a device historically used for communicating over greatly extended distances. It dates to the Paleolithic period, being found in Ukraine dating from 17,000 BC. Anthropologist Michael Boyd, a Bullroarer expert, documents a number found in Europe, Asia, the Indian sub-continent, Africa, the Americas, and Australia.
The bullroarer has sometimes been incorrectly used as a means of seeming to demonstrate the Doppler effect in sound waves. In such cases, an incorrect explanation which might be given is that as the instrument travels around its circular path, its perceived pitch may, to a third party, seem to appear to rise and fall as it moves closer and farther away, respectively. This explanation is credible only because it is hard to keep track of the circling blade's location and at the same time to associate that with the bullroarer's pitch changes. In fact, when the bullroarer is whirled around one's head in a horizontal plane, the pitch rises and falls in its usual manner even though the spinning neither approaches much nor retreats much from the ears of the whirler. There is essentially no Doppler effect involved in that case, only the speeding up and slowing of the axially rotating blade.
The greatest pitch variations are not caused by the approach and recession of the spinning blade at all. Rather, as the blade spins, it winds up or loosens the twisting of the cord that holds the blade. When the twist in one direction gets tight enough, the blade spin will slow and then it will reverse its spin and unwind rapidly, and will continue that direction of spin until the cord twist tightens again. At that time, the blade will reverse its spin direction again. During the reversals the blade's rotational speed about its long axis rises and falls. This variation in its own rapid rate of spin is what produces the pitch variation. There is no necessary link between a bullroarer's pitch and how fast the entire bullroarer is going around on its cord in its large circle, or where the blade is at any given time in relation to a hearer, or whether it is approaching or receding from that listener. In fact, two listeners on opposite sides of the person whirling the bullroarer will hear simultaneous and nearly identical rises and falls of the pitch even though the blade will be approaching one and going away from the other at any given time.
Design, use, and sound 
A bullroarer consists of a weighted aerofoil (a rectangular thin slat of wood about 15 cm (6 in) to 60 cm (24 in) long and about 1.25 cm (0.5 in) to 5 cm (2 in) wide) attached to a long cord. Typically, the wood slat is trimmed down to a sharp edge around the edges, and serrations along the length of the wooden slat may or may not be used, depending on the cultural traditions of the region in question.
|Wikisource has the text of the 1911 Encyclopædia Britannica article Bullroarer.|
The cord is given a slight initial twist, and the roarer is then swung in a large circle in a horizontal plane, or in a smaller circle in a vertical plane. The aerodynamics of the roarer will keep it spinning about its axis even after the initial twist has unwound. The cord winds fully first in one direction and then the other, alternating.
It makes a characteristic roaring vibrato sound with notable sound modulations occurring from the rotation of the roarer along its longitudinal axis, and the choice of whether a shorter or longer length of cord is used to spin the bullroarer. By modifying the expansiveness of its circuit and the speed given it, and by changing the plane in which the bullroarer is whirled from horizontal to vertical or vice versa, the modulation of the sound produced can be controlled, making the coding of information possible. The low-frequency component of the sound travels extremely long distances, clearly audible over many miles on a quiet night.
Bullroarers have been used variously as musical instruments, ritualistic devices, and long-range communication devices by many cultures over at least the last 19,000 years. For example, due to the eerie sound produced, bullroarers were sometimes used in late-nineteenth- and early-twentieth-century America in the southern United States for playing elaborate practical jokes on superstitious country dwellers.
In culture 
|North American Indian Bullroarers.|
This instrument has been used by numerous early and traditional cultures in both the northern and southern hemispheres but in the popular consciousness it is perhaps best known for its use by Australian Aborigines (it is from one of their languages that the name turndun comes).
Australian Aboriginal culture 
Bullroarers have accompanied the didgeridoos in initiation ceremonies and in burials to ward off evil spirits, bad tidings and especially women and children. Bullroarers are considered secret men's business by some Aboriginal tribal groups, and hence forbidden for women, children, non-initiated men, or outsiders to even hear. Fison and Howitt documented this in "Kamilaroi and Kurnai" (page 198). Anyone caught breaching the imposed secrecy was to be punished by death.
They are used in men's initiation ceremonies, and the sound they produce is considered in some indigenous cultures to represent the sound of the Rainbow Serpent. In the cultures of southeastern Australia, the sound of the bullroarer is the voice of Daramulan, and a successful bullroarer can only be made if it has been cut from a tree containing his spirit.
In 1987, Midnight Oil included a recording of a bullroarer on their album Diesel and Dust (at the beginning of the song "Bullroarer") inadvertently causing offense to the Aboriginal people of Central Australia from whom the recording was taken.
Bullroarers have sometimes been referred to as "wife-callers" by Australian Aborigines.
British Isles 
In the British Isles, the bullroarer—under a number of different names and styles—is used chiefly for amusement, although formerly it may have been used for ceremonial purposes. In parts of Scotland it was known as a "thunder-spell" and was thought to protect against being struck by lightning. In the Elizabeth Goudge novel Gentian Hill (1949), set in Devon in the early 19th century, a bullroarer figures as a toy cherished by Sol, an elderly farm labourer, who being non-verbally gifted, uses it occasionally to express strong emotion; however, the sound it makes is perceived as being both eerie and unlucky by two other characters, who have an uneasy sense that ominous spirits of the air ("Them") are being invoked by its whirring whistle.
Scandinavian Stone Age cultures used the bullroarer. In 1991, the archeologhists Hein B. Bjerck and Martinius Hauglid found a 6.4 cm-long piece of slate that turned out to be a 5000-year-old bullroarer (called a "brummer" in Scandinavia). It was found in Tuv in northern Norway, a place that was inhabited in the Stone Age.
The Dogon use bullroarers to announce the beginning of ceremonies conducted during the Sigui festival held every sixty years over a seven-year period. The sound has been identified as the voice of an ancestor from whom all Dogon are descended.
Native North American 
Almost all the native tribes in North America used bullroarers in religious and healing ceremonies and as toys. There are many styles.
Native South American 
- Haddon, The Study of Man, p. 219: "Prof. E. B. Tylor informs me that the name of 'bull-roarer' was first introduced into anthropological literature by the Rev. Lorimer Fison, who compares the Australian tundun to 'the wooden toy which I remember to have made as a boy, called a 'bull-roarer',' and this term has since been universally adopted as the technical name for the implement." [Fison and Howitt, Kamilaroi and Kurnai, 1880. p. 267.]
- Gregor, Thomas. Anxious Pleasures: The Sexual Lives of an Amazonian People. University Of Chicago Press (1987). p. 106 "Today we know that the bullroarer is a very ancient object, specimens from France (13,000 B.C.) and the Ukraine (17,000 B.C.) dating back well into the Paleolithic period. Moreover, some archeologists, most notable Michael Boyd—notably, Gordon Willey (1971,20) and Michael Boyd (Leisure in the Dreamtime 1999,21) —now admit the bullroarer to the kit-bag of artifacts brought by the very earliest migrants to the Americas."
- Bayley, Harold. The Lost Language of Symbolism: An Inquiry into the Origin of Certain Letters, Words, Names, Fairy-Tales, Folklore, and Mythologies Book Tree (2000). p. 86: "The bullroarer, used always as a sacred instrument, is still employed n New Mexico, the Malay Peninsula, Ceylon, New Zealand, Africa, and Australia, and under the name of Rhombus it figured prominently in the Mysteries of Ancient Greece."
- Fransciscan Fathers, An Ethnologic Dictionary of the Navaho Language, p. 414.
- Young, R & Morgan, W An Analytical Lexicon of Navajo, (1992) University of New Mexico Press ISBN 0-8263-1356-6, p. 461.
- Powell, Ninth Annual Report of the Bureau of Ethnology, p. 477: "Fig. 430.—Rhombus of the Apache."
- Kroeber, "Ethnology of the Gros Ventre", p. 190: "Fig. 26 (50-1788). Bull-roarer, Length, 56 cm."
- Haddon, The Study of Man, p. 221: "Fig 38. Bull-Roarers from the British Islands."
- Haddon, The Study of Man,p 225: "Those given to me were made for me, and may not represent the common form of bull-roarer in the north-east corner of Ireland. My informant stated that once when, as a boy, he was playing with a 'boomer' an old country woman said it was a 'sacred' thing."
- Haddon, The Study of Man, p. 222: "It was believed that the use of this instrument [thunder-spell] during a thunder-storm saved one from being struck with 'the thun'er-bolt'."
- Goudge, Elizabeth. Gentian Hill, New York: Coward-McCann, Inc., 1946, pp. 71-72, 168, 315-321, 346-348, 354.
Other sources 
- Franciscan Fathers. An Ethnologic Dictionary of the Navaho Language. Saint Michaels, Arizona: Navajo Indian Mission (1910.
- Haddon, Alfred C. The Study of Man. New York: G.P. Putnam's Sons (1898).
- Lang, A. "Bull-roarer", in J. Hastings, "Encyclopedia of Religion and Ethics II", p. 889-890 (1908-1927).
- Kroeber, A.L. "Ethnology of the Gros Ventre", Anthropological Papers of the American Museum of Natural History pp. 145–283. New York: Published by Order of the Trustees (1908).
- Powell, J.W. (Director). Ninth Annual Report of the Bureau of Ethnology to the Secretary of the Smithsonian Institution 1887-'88. Washington, D.C.: Government Printing Office (1892).
- Hart, Mickey Planet Drum, A Celebration of Percussion and Rhythm pp. 154–155. New York: HarperCollins (1991).
- Battaglia, R., Sopravvivenze del rombo nelle Province Venete (con 7 illustrazioni), Studi e Materiali di Storia delle Religioni 1 (1925), pp. 190–217.