This Woman's Polyphonic Overtone Singing Doesn't Sound Humanly Possible

When you watch German musician Anna-Maria Hefele demonstrate a few polyphonic overtone singing techniques, you will get chills. "Overtone singing is a voice technique where one person sings two notes at the same time," explains Hefele in the video above. On her website, Hefele says this style is originally from Mongolia, locally known as Sygyt. Watch Hefele show off her perfect control, as she is able to sustain one constant low note, while simultaneously singing a high-pitched scale. It seems i...