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Polyphonic Overtone Singing Explained Visually With Spectrograms

Posted by timothy on from the coolest-thing-you'll-hear-today dept.

New submitter Tucano writes The overtone singer Anna-Maria Hefele can sing two notes at the same time. In her latest video, spectrograms and frequency filters are used to explain how she can produce two melody lines at the same time, and how she uses her mouth to filter the frequencies of her voice. When the voice produces a sound, many harmonics (or overtones) sound at the same time, and we normally hear this as a single tone. In overtone singing, the mouth filters out all harmonics but one, and the one that remains is amplified to become louder. This is then perceived as a separate tone, next to the fundamental. In her video, Anna-Maria shows techniques that become increasingly advanced. She shows the overtone scale (steady fundamental, moving overtone), the undertone scale (steady overtone, moving fundamental), parallel movement and opposing movement of overtone and fundamental, and even complex compositions with two separate melody lines.

7 of 51 comments (clear)

  1. Reminds me of Tuvan throat singing by Muad'Dave · · Score: 3, Informative

    If you're not familiar with Tuvan throat singing, check out the documentary Genghis Blues that follows blind blues musician Paul Pena on his trip to Tuva to compete in their throat singing competition.

    From his bio:

    Paul first heard a fragment of harmonic singing on a shortwave Radio Moscow broadcast on December 29, 1984 and he was so struck by it, he spent almost eight years trying to track down its source. In 1991 he was finally able to locate a recording of Tuvan music and taught himself the vocal techniques known as 'Khoomei, Sygyt, and Kargyraa'. In addition, he learned a good bit of the Tuvan language using English-Russian and Russian-Tuvan dictionaries and an obsolete 'Opticon' scanning device which translates text into sensations. In 1993, Paul attended a concert sponsored by the Friends of Tuva organization and met Kongar-ol Ondar after the performance. Paul gave Kongar-ol an impromptu demonstration--and astonished him with his talent and mastery of traditional Tuvan singing. The two men formed a strong friendship along with their musical collaboration.

    In 1995, Kongar-ol invited Paul to sing at the second international Khoomei Symposium and contest, held in Tuva's capital city, Kyzyl. Ralph Leighton and the "Friends of Tuva" sponsored his trip.

    --
    Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
    1. Re:Reminds me of Tuvan throat singing by Ol+Biscuitbarrel · · Score: 3, Informative

      Cowboy singer Arthur Miles cut a record in the 1930s using overtone singing. It seems to be something people inevitably develop from just messing around with the possibilities of the human voice.

  2. Just one's mouth can make some powerful music by CRCulver · · Score: 3, Informative

    A few years ago I became interested in Kyrgyz folk music through the Smithsonian Folkways disc Tengir-Too . Like all Central Asian nomadic peoples, the Kyrgyz have cultivated the jew's harp, or kobuz. This instrument has only one vibrating element, and though it can produce only a single tone, the performer can create a variety of sounds through changing the contours of his mouth and lips. It's a humble instrument but so endless. During a trip to Kyrgyz, I bought a kobuz of my own, and though I'll probably never master it enough produce the virtuosic songs of the musicians on that disc, I'll certainly never get bored.

    1. Re:Just one's mouth can make some powerful music by Solandri · · Score: 3, Informative

      the Kyrgyz have cultivated the jew's harp, or kobuz. This instrument has only one vibrating element, and though it can produce only a single tone, the performer can create a variety of sounds through changing the contours of his mouth and lips. It's a humble instrument but so endless.

      These instruments and overtone singing take advantage of something most people know nothing about - how our perception of sound works. When you hear, say, a violin, you aren't hearing a "violin sound". You're hearing a combination of sinusoidal waves - a fundamental combined with multiple overtones. Those of you well-versed in math may recognize this as a Fourier series. Our ears are designed to perform a Fourier transform on incoming sounds, and separate out the individual frequencies. Individually these sinusoids are no different from the sinusoids generated by any other instrument (or any sound source for that matter). The stimulation a violin gives your ear at 440 Hz is exactly the same as what a horn gives, a voice gives, or even a jet engine gives at that one frequency - a sinusoid.

      It's the ratio of the magnitudes of different frequencies (fundamental + overtones) which make a violin sound like a violin. A horn has a different ratio of magnitudes at the different overtones. Same with a voice (each individual voice - that's how you recognize someone's voice). Same with a jet engine. The raw data our brain gets from the ear is just a bunch of separate frequencies and and their magnitudes. It then compares the ratios of potential fundamentals + overtones and says, "oh, that's a violin". It always amazed me that you listen to an orchestra and pick out the individual instruments - all their frequencies and magnitudes are overlapping into a mishmash of sound. When I later learned about spread spectrum multiplexing, that's when I understood your brain is doing the equivalent of orthgonal frequency division multiplexing (which is the technology used for LTE). Even though the frequencies generated by the instruments in an orchestra overlap into a mishmash of sound, the ratios of their overtones are orthogonal enough that if you listen carefully you can pick out the individual instruments. Exactly how your cell phone picks up the signal intended for it from the mishmash of signals the tower puts out for all phones.

      In many ways, a Jew's harp and overtone singing are akin to analog sound synthesis. If you thought the high pitch she was singing sounded vaguely flute- or recorder-like, it's because those instruments have very close to a pure sinusoidal waveform (fundamental, very little overtones). The individual overtone she is amplifying is sinusoidal in waveform, so your brain interprets it as flute- or recorder-like. It's very similar to how the early synthesizers worked (before computer memory became cheap enough to sample everything). The name comes from frequency modulation synthesis - you modulate the magnitudes of the different frequencies (overtones) to alter what instrument the sound sounds like. Match the pattern of violin overtones and it sounds like a violin. Match the pattern of horn overtones and it sounds like a horn. The overtone singer has only mastered modulating the fundamental and one overtone, which limits her synthesis capabilities. But if she's capable of modulating a second or third overtone, she could start making her voice sound like different instruments. Just like an old analog FM synthesizer.

  3. Re:How do you do it? by Anonymous Coward · · Score: 2, Informative

    There are several tutorials on youtube on how to do overtone (also called throat) singing. She doesn't cover it, because probably there's enough of it already.

  4. I can do it! by Charliemopps · · Score: 3, Informative

    I've been doing this since I was about 10yrs old. Clearly this woman is far far superior at it than I've ever been. At best, I can hold the fundamental and move the overtone around in a slide sort of way. The way she's doing stepping is amazing. When I started doing this, it was more of a magic trick to me. I'd say "Listen! I can have 2 voices at once!" I had no idea what I was really doing.

    For those wondering how to do it. Imagine humming with your mouth open. You have to close off your mouth in the same way you do when you drink through a straw and then hum like that. The fundamental feels very nasally to the singer. It makes your sinuses vibrate.

    To get the overtone, I put the tip of my tong, right behind my front teeth on the roof of my mouth like when I make an "L" sound. Then change the shape of your tong like when you say "La" or "Lu" or "Lo" but never remove your tong from the roof of your mouth. The shape of your tong for each of those phonics gives you different tones. That's of course, how I do it. And I'm totally untrained so take it with a grain of salt.

  5. Re:How do you do it? by ripvlan · · Score: 3, Informative

    This is the second video from her that I've seen. I really liked this one because she explained what she was doing. The first was just her singing and I didn't "get it."

    Look in the suggested links on YouTube - you'll see one from "Yuichi Tuba" who goes into the basics. He talks about where to put your tongue, how to shape it, and how to practice. https://www.youtube.com/watch?...

    Something fun to go home and try. Better than teaching the kid how to make farting noises under his arm.