New Zealand Maōri People Wind Instrument (Bullroarer): "Purerehua"

This "purerehua," Maōri for butterfly, is a bullroarer. It consists of a thin, flat piece of wood, usually the heart wood of matai.

The player swings the bullroarer lasso style over his head, creating a humming sound. Some natives believe that this sound is caused by the wairua, or soul, of the player.

The purerehua was used in the past in a ceremony performed to bring rain. The player would throw a handful of ashes toward the south (the rainy quarter) and sound his purerehua by swinging it round, at the same time turning his back on the south in an insulting manner. The south would become angry and send a storm.

The bullroarer is also known to the Maōri as a "huhu," among several other names.
Source:
http://9waysmysteryschool.tripod.com/sacredsoundtools/id9.html
http://nzetc.victoria.ac.nz/tm/scholarly/tei-BesGame-t1-body-d9-d1-d9.html