1. Physics of Living Systems
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Overtone focusing in biphonic Tuvan throat singing

  1. Christopher Bergevin  Is a corresponding author
  2. Chandan Narayan
  3. Joy Williams
  4. Natasha Mhatre
  5. Jennifer Steeves
  6. Joshua GW Bernstein
  7. Brad Story  Is a corresponding author
  1. York University, Canada
  2. Western University, Canada
  3. Walter Reed National Military Medical Center, United States
  4. University of Arizona, United States
Research Article
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Cite this article as: eLife 2020;9:e50476 doi: 10.7554/eLife.50476

Abstract

Khoomei is a unique singing style originating from the Central Asian republic of Tuva. Singers produce two pitches simultaneously: a booming low-frequency rumble alongside a hovering high-pitched whistle-like tone. The biomechanics of this biphonation are not well-understood. Here, we use sound analysis, dynamic magnetic resonance imaging, and vocal tract modeling to demonstrate how biphonation is achieved by modulating vocal tract morphology. Tuvan singers show remarkable control in shaping their vocal tract to narrowly focus the harmonics (or overtones) emanating from their vocal cords. The biphonic sound is a combination of the fundamental pitch and a focused filter state, which is at the higher pitch (1-2 kHz) and formed by merging two formants, thereby greatly enhancing sound-production in a very narrow frequency range. Most importantly, we demonstrate that this biphonation is a phenomenon arising from linear filtering rather than a nonlinear source.

Data availability

All data files (audio and imaging), as well as the relevant analysis software, are available via datadryad.org, https://doi.org/10.5061/dryad.cvdncjt14

The following data sets were generated
    1. Bergevin
    2. Christopher
    (2020) Overtone focusing in biphonic Tuvan throat singing
    Dryad Digital Repository, https://doi.org/10.5061/dryad.cvdncjt14.
    https://doi.org/10.5061/dryad.cvdncjt14

Article and author information

Author details

  1. Christopher Bergevin

    Physics and Astronomy, York University, Toronto, Canada
    For correspondence
    cberge@yorku.ca
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4529-399X

  2. Chandan Narayan

    Languages, Literatures and Linguistics, York University, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.

  3. Joy Williams

    York MRI Facility, York University, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.

  4. Natasha Mhatre

    Biology, Western University, London, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3618-306X

  5. Jennifer Steeves

    Psychology, York University, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.

  6. Joshua GW Bernstein

    National Military Audiology and Speech Pathology Center, Walter Reed National Military Medical Center, Bethesda, United States
    Competing interests
    The authors declare that no competing interests exist.

  7. Brad Story

    Speech, Language, and Hearing Sciences, University of Arizona, Tucson, United States
    For correspondence
    bstory@email.arizona.edu
    Competing interests
    The authors declare that no competing interests exist.

Funding

Natural Sciences and Engineering Research Council of Canada (RGPIN-430761-2013)

  • Christopher Bergevin

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Human subjects: Data were collected with approval of the York University Institutional Review Board (IRB protocol to Prof. Jennifer Steeves) This study was approved by the Human Participants Review Board of the Office of Research Ethics at York University (certificate #2017-132) and adhered to the tenets of the Declaration of Helsinki. All participants gave informed written consent and consent to publish prior to their inclusion in the study.

Reviewing Editor

  1. Timothy D Griffiths, University of Newcastle, United Kingdom

Publication history

  1. Received: July 24, 2019
  2. Accepted: January 31, 2020
  3. Accepted Manuscript published: February 12, 2020 (version 1)
  4. Accepted Manuscript updated: February 17, 2020 (version 2)
  5. Version of Record published: March 10, 2020 (version 3)

Copyright

© 2020, Bergevin et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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    Speech Biomechanics: Shaping new sounds

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