The famous didgeridoo of aboriginal Australians is made from a length of eucalyptus branch hollowed out by termites. Its blowing end is wide, usually smoothed with a beeswax coating, and the player uses a sophisticated technique with slack embouchure producing low drone notes, pulsing his breath, utilizing mouth resonance and adding in vocal yelps and barks that intermodulate with the blown sound, which is maintained continuously by circular breathing.