The American Sleep Apnea Association reported that:

“The first published article on the possible effect of playing a wind instrument on OSA was an investigation of playing the didgeridoo, a drone instrument traditional among Australian aborigines. Results of the study, conducted in Switzerland by Milo A. Puhan and others, were published online by the British Medical Journal in December 2005.Puhan and his colleagues worked with 25 patients with moderate obstructive sleep apnea (apnea-hypopnea indexes between 15 and 30). Fourteen were supplied four-foot-long plastic didgeridoos, given four lessons on the instrument spaced over an eight-week period, and instructed to practice at least 20 minutes a day five days a week. The 11-person control group was placed on a four-month waiting list for their own didgeridoos and lessons.The physiological benefit of didgeridoo playing is believed to stem from an action called circular breathing, in which the player inhales through the nose while maintaining an uninterrupted outflow into the instrument through the mouth, using the cheeks as bellows. This produces a continuous note sustained far longer than would be possible with a single breath. The following link shows circular breathing in action: http://tiny.cc/asaadidgeridoo. At the conclusion of the four months, the investigators found that the didgeridoo players’ apnea-hypopnea index had dropped from an average of 21 to 11.6. (The AHI of the untreated control group decreased as well, but only to 15.4.) The didgeridoo players also showed a marked improvement in their level of daytime sleepiness. And the participants proved to be enthusiastically compliant with their instructions, honking on their instruments an average of almost six days a week although five was all that was asked for.