BullroarerThe bullroarer, rhombus, or turndun, is an ancient ritual musical instrument and a device historically used for communicating over great distances. It consists of a piece of wood attached to a string, which when swung in a large circle produces a roaring vibration sound. It dates to the Paleolithic period, being found in Ukraine dating from 18,000 BC. Anthropologist Michael Boyd, a bullroarer expert, documents a number found in Europe, Asia, Africa, the Americas, and Australia. In Ancient Greece it was a sacred instrument used in the Dionysian Mysteries and is still used in rituals worldwide. It was a prominent musical technology among the Australian Aboriginal people, used in ceremonies and to communicate with different people groups across the continent. aerophone