1. Physics of Living Systems
Download icon

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
  • Cited 1
  • Views 5,336
  • Annotations
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.

Metrics

  • 5,336
    Page views
  • 199
    Downloads
  • 1
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)

Categories and tags

Research organism

    1. Related to

    Speech Biomechanics: Shaping new sounds

    Timothy D Griffiths et al.
  2. Further reading

Further reading

    1. Physics of Living Systems

    Speech Biomechanics: Shaping new sounds

    Timothy D Griffiths et al.
    Insight

    MRI experiments have revealed how throat singers from Tuva produce their characteristic sound.

  2. Listen to Chandan Narayan discuss throat singing

    Podcast

    A new study reveals how throat singing is produced.

    1. Developmental Biology
    2. Physics of Living Systems

    Cost-precision trade-off relation determines the optimal morphogen gradient for accurate biological pattern formation

    Yonghyun Song, Changbong Hyeon
    Research Article Updated

    Spatial boundaries formed during animal development originate from the pre-patterning of tissues by signaling molecules, called morphogens. The accuracy of boundary location is limited by the fluctuations of morphogen concentration that thresholds the expression level of target gene. Producing more morphogen molecules, which gives rise to smaller relative fluctuations, would better serve to shape more precise target boundaries; however, it incurs more thermodynamic cost. In the classical diffusion-depletion model of morphogen profile formation, the morphogen molecules synthesized from a local source display an exponentially decaying concentration profile with a characteristic length λ. Our theory suggests that in order to attain a precise profile with the minimal cost, λ should be roughly half the distance to the target boundary position from the source. Remarkably, we find that the profiles of morphogens that pattern the Drosophila embryo and wing imaginal disk are formed with nearly optimal λ. Our finding underscores the cost-effectiveness of precise morphogen profile formation in Drosophila development.