Throat singing sounds as if someone is singing while at the same time being accompanied by another instrument. But, in fact, all the sound is coming from just the singer’s voice. The sound of throat singing is usually a combination of low, droning hums and sharp, high-pitched melodies. Throat singing is also known as harmonic or overtone singing because the high-pitched sounds are harmonics, or overtones, of the lowest sound. Both the vocal folds and the vocal tract are manipulated to make the unique sounds of throat singing. In order to make the lowest, droning notes, throat singers control how, when and what parts of the vocal folds (vocal cords) vibrate. The special methods used also make the higher notes stronger. The higher notes are known as harmonics (overtones). Harmonics are present in normal speech and singing, but the special shaping of the vocal tract during throat singing makes them much louder. In some singing styles, the highest note can be up to 43 times higher than the lowest note!
Tuvan throat singing (performed by Vasilii Khuurak):