I first heard a Siberian throat singer on the History Channel a few months ago, but I never really took the time to learn more about it. It wasn't really explained in the program (and was actually more of a break in the documentary), so I figured that this blog would be as good a place as any to explore the practice.
To begin, throat singing involves the ability to produce two, or more, notes simultaneously; the higher notes are normally harmonic notes (similar to those on guitars) and the lower notes are simply referred to as fundamental tones. Some throat singers can also produce sounds resembling the chirping of birds, the beat of a horse's hooves, or the sound of a reindeer breathing.
People who have this ability produce multiple notes by applying tension to the vocal cords and the surrounding areas, such as the mouth and even the lungs. The tongue, however, is only used to change the resonance and shape of the mouth, rather than to produce the vibrations (and, therefore, the sounds). The harmonic notes mentioned above can be amplified by moving the tongue and lips, thus creating a smaller or larger space for the sound to resonate.
This form of vocalization is primarily practiced in Asia, but also occurs in regions of South Africa, Northern Canada, and Greenland. A more precise list includes Tibet, Tuva (essentially southern Russia), Khakkasia (a republic east of Tuva), Bashkortostan (located in southwest Russia), Mongolia, and the Chukchi peoples of Northern Russia.
The latter group originally used throat singing to represent the breathing of reindeer, as mentioned above. However, scholars are uncertain when the practice began, or if the tribes were influenced by people from neighboring countries and regions.
In most of these groups, throat singing is practiced by men, especially in Tuva and Mongolia. Women of the South African Xosa tribe are one of the few exceptions.
Side Note: There are approximately 15,000 Chukchi in the world. The word Chukchi is derived from Chauchu, which actually means "rich in reindeer." The religious practices of the tribe were prohibited by the Soviet Union until the 1920s and, after the dissolution of the USSR, their farms were reorganized. This essentially destroyed the village-based lifestyle and economy of the region.
(Source: Wikipedia - Chukchi People)