Australian physicists say they have discovered the secret of skilled didgeridoo players. Read more about this below the video player.

July 7, 2005—The didgeridoo (or yidaki in the Yolngu language of northern Australia), like the one being played in this National Geographic video, is traditionally made from a small tree trunk hollowed out by termites. It usually plays only one note, but the most skilled players manage to produce a great variety of timbres and rhythms as they alter their tongue position and mouth shape.

Now Australian physicists say they have discovered the secret of skilled didgeridoo players.

What separates an expert from a novice is the opening and closing of the glottis, the part of the windpipe that contains the vocal cords. A skilled player subconsciously reduces the opening of the glottis to set up strong resonances at different frequencies inside the mouth.

The vocal cords mimic the positions used when producing vowel sounds, explain Joe Wolfe and his colleagues from the University of New South Wales in this week's journal Nature. If the vocal tract remains open, as in normal breathing, the lungs absorb much of the sound.

The researchers suggest that didgeridoo playing may be similar to playing a brass instrument, in which changes to the vocal tract can also influence the quality of the sound produced.

—David Braun