The bullroarer, rhombus, or turndun is an ancient musical instrument used in rituals and for sending messages over long distances. It is made of a piece of wood tied to a string. When the string is swung in a large circle, the wood creates a loud, vibrating sound that resembles a roar.

This instrument was used during the Paleolithic period. Examples from 18,000 BC have been found in Ukraine. Anthropologist Michael Boyd, an expert on bullroarers, has recorded examples of the instrument in Europe, Asia, Africa, the Americas, and Australia. In Ancient Greece, it was considered sacred and used in religious ceremonies called the Dionysian Mysteries. Today, it is still used in rituals around the world. Among Australian Aboriginal people, it was an important tool for music and communication during ceremonies and for connecting with other groups across the continent.

Many cultures believe that the sounds made by the bullroarer have the ability to protect people from harmful forces.

Design, use, and sound

A bullroarer is made of a flat, thin piece of wood shaped like a rectangle. The wood is about 15 to 60 centimeters (6 to 20 inches) long and 1.2 to 5 centimeters (0.5 to 2 inches) wide. It is attached to a long rope. The wood is often sharpened to a thin edge, and some cultures may add small cuts along the length of the wood, while others do not.

The rope is twisted slightly, and the bullroarer is then moved in a large circle in a horizontal plane or a smaller circle in a vertical plane. As the bullroarer spins, the force from its movement keeps it rotating around its center even after the initial twist is released. The rope winds completely in one direction and then the opposite direction, repeating this pattern.

The bullroarer creates a loud, vibrating sound that changes in tone. These changes depend on how fast it spins, the size of the circle it moves in, and whether it is spun horizontally or vertically. These variations in sound can be used to send messages.

The deep, low part of the sound can travel very far. On a quiet night, it can be heard clearly from many miles away.

In culture

Bullroarers have been used by many cultures around the world for at least 19,000 years. These tools have served as musical instruments, religious objects, and tools for sending messages over long distances. They have been used by people in both the Northern and Southern Hemispheres, but are most widely known in the culture of Aboriginal Australians. The word "turndun," used by Aboriginal people, is where the name "bullroarer" comes from.

Henry Cowell, a composer, wrote a musical piece that included bullroarers along with string instruments. The Kate Bush Before The Dawn concerts in London in 2014 also used a bullroarer.

Bullroarers have been used in ceremonies to protect people from evil spirits and during burials. In many Aboriginal groups, bullroarers are considered "secret men's business," meaning only certain men are allowed to use or hear them. Women, children, and outsiders are not permitted to hear or use them. This rule was recorded by Fison and Howitt in their book Kamilaroi and Kurnai on page 198. People who broke these rules could be punished severely.

In some cultures, bullroarers are used in ceremonies to welcome new members of a group. In parts of Australia, the sound of a bullroarer is believed to represent the voice of the Rainbow Serpent. In southeastern Australia, the sound is thought to be the voice of Daramulan, and a bullroarer can only be made from a tree believed to contain his spirit.

Bullroarers have also been used in Aboriginal art and are sometimes called "wife-callers" by Indigenous Australians. In the 1988 film Crocodile Dundee II, actor Paul Hogan used a bullroarer. In 1946, John Antill included a bullroarer in his ballet Corroboree.

An Australian band called Midnight Oil used a recording of an imitation bullroarer on their 1987 album Diesel and Dust. The band’s drummer explained that they used an imitation version instead of a real bullroarer to avoid disrespecting cultural traditions.

In Ancient Greece, bullroarers were used in religious ceremonies for the goddess Cybele. They were called "rhombos," a word that describes both their shape and the sound they make.

In Great Britain and Ireland, bullroarers were used for fun and sometimes in ceremonies. In Scotland, they were called "thunder-spells" and were believed to protect people from lightning. In a novel called Gentian Hill, a character used a bullroarer as a toy but others found its sound strange and unlucky.

Scandinavian Stone Age cultures used bullroarers. In 1991, archaeologists found a 5,000-year-old bullroarer in Norway.

The Dogon people of Africa use bullroarers during the Sigui festival, which happens every 60 years. The sound is believed to be the voice of an ancestor.

Native Hawaiians use two types of bullroarers: a large one made from a coconut shell and a smaller one made from a kamani nut.

The Māori of New Zealand use a bullroarer called the pūrerehua, made from wood, stone, or bone. It is used for healing or to bring rain.

Most Native American tribes used bullroarers in religious ceremonies, healing rituals, and as toys. There are many different styles.

In Alaska, the Inupiat people used bullroarers called imigluktaaq or imigluktaun. These were made from bone or wood and used as toys.

In 1963, a woman from Banks Island used a bullroarer to scare off polar bears. Some groups, like the Aleut, Eskimo, and Inuit, used bullroarers as toys or musical instruments but preferred drums and rattles.

The inland Pomo tribes of California used bullroarers in a ceremony called the xalimatoto or Thunder ceremony. Four men would spin bullroarers made from cottonwood to mimic the sound of thunder.

Shamans in the Amazon basin, such as those in Tupi, Kamayurá, and Bororo cultures, used bullroarers in rituals. In Tupian languages, the bullroarer is called hori hori.