The “khoomei” or throat singing is an ancestral overtone singing that consists in reproducing natural sounds like the flow of water, the breath of wind, the echo of the mountains, the rumble of thunder, the singing of birds, etc. An overtone singing is characterised by a vocal technique that allows to make simultaneously several sounds with a single vocal organ, combining different voices and different ways to place the tongue or the lips.
The singer uses his/her throat to give out a continuous deep sound, and, at the same time, using his/her tongue to control the breathed out air, he/she manages to modulate the resonance in more high-pitched harmonics. This singing can be related to the mouth harp, this small instrument that also produces several different sounds: drone, singing, and counterpoint.
A khoomei singer must know the different organs very well to use them with precision: pharynx, vocal cords, oral cavity, tongue, lips, and nasal cavity. Good khoomei singers can modify their own frequency by adapting the volume of the oral cavity, the opening of the mouth, and the position of the lips.
Overtone singings have been sung for a long time in many cultures across the world, especially in Asia, by Mongolians, Tuvas, Bachkirs, Altai people, and Tibetan people, but also in Italy by Sardinian people, in India by Rajasthan people, or in South Africa by Xhosa people.
Some have noticed that a third sound could be produced with Tuvan techniques, but it's still impossible to know if this third sound can be controlled. This third sound seems more to look like the mouth harp's counterpoint.
So, khoomei is nothing but an overtone singing. But it's divided into six categories: khamrin khoomii (nasal khoomei), bagalzuuriin khoomii (glottal khoomei), tseejnii khondiin khoomii (chest cavity khoomei), uruulin khoomii (labial khoomei), khosmoljin or turlegt khoomii (khoomei combined with long song), tagnain khoomi (palatal khoomei). The difference lies in the technique used.
Khoomei is said to come from the area of Khovd, in the Altai range, western Mongolia. The four most famous khoomei singers of Mongolia are Suindui Jajaa, Tserendorj, Ganbold, and Odsuren, and they all come from Khovd. Besides Ganbold worked as sound operator on the original soundtrack of the famous movie “Queen Mandukhai the wise”. But khoomei also extended to other areas sometimes really far from Khovd.
Khoomei, and more generally all types of overtone singing, is also supposed to have therapeutic virtues. Experiments led by doctors and musicians have often shown that there was a connection between mental or physical health and music. When it's used for therapeutic purposes, khoomei's main goal is to bring back concentration and sanity. Some shamanic experiences and Tibetan singings are very close to this goal too.
For example, this type of singing is said to have real effects on stammer, blocks in the throat, confidence in one's voice, inhibition, respiratory problems, anxiety, tiredness, childbirth pain, etc. but no study confirms the efficacy of the practice.
And moreover, these effects are said to affects, not only humans, but also animals!