Note: an explanation of the significance of the bullroarer

The bull-roarer was often used by the central tribes to warn women and children away from totemic ceremonies, particularly during initiation. The sound was regarded as the voice of the spirit come to take the boys away. In some cases bull-roarers were associated with various totemic or ceremonial objects known as churinga which women or uninitiated men were forbidden to see. Penalties were severe; blinding by fire-stick and even death. Beliefs varied considerably but each individual possessed a churinga in wood or stone with which his or her spirit being was associated. The smallest bull-roaring churinga was called Namatwinna or Namatuna because it had to be struck against the ground and grass to make it whirl and sound properly. It had none of the sacred attributes of the churinga but could be used for magic purposes, such as charming women. Sometimes they were lent for a time.

For an explanation of the wider significance of the bullroarer see Bull-roarers - by Bethe Hagens