In Australia,The didgeridoo, traditionally played by men in ceremony, is a purely Aboriginal invention and is thought to be the world's oldest wind instrument. The didgeridoo is deceptively simple in design but is, in fact, a complicated instrument.
A termite-hollowed didgeridoo tends to be wider in diameter at the bottom than the top, which creates unusual resonant frequencies. The vocalizations and circular breathing technique required to play it initiate sound wave interactions between the players' lips and vocal tract, and within the instrument itself. This creates the didgeridoo's distinctive sound.
I have played ones made in Oz , but prefer the PVC pipe "didge" because it is lighter and easier for me to play. Not to mention the fact that you can throw a plastic one in a canoe and there is no need to worry about messing it up or breaking it.
See you on the trail!