Bullroarer
The 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.
Many different cultures believe that the sounds they make have the power to ward off evil influences.