Gerrit Bloothooft, Eldrid Bringmann, Marieke van Cappellen, Jolanda B. van Luipen, and Koen P. Thomassen : Acoustics and perception of overtone singing

Published Online: 04 June 1998
Accepted: June 1992
The Journal of the Acoustical Society of America 92, 1827 (1992);

Overtone singing, a technique of Asian origin, is a special type of voice production resulting in a very pronounced, high and separate tone that can be heard over a more or less constant drone. An acoustic analysis is presented of the phenomenon and the results are described in terms of the classical theory of speech production. The overtone sound may be interpreted as the result of an interaction of closely spaced formants. For the lower overtones, these may be the first and second formant, separated from the lower harmonics by a nasal pole‐zero pair, as the result of a nasalized articulation shifting from /c/ to /a/, or, as an alternative, the second formant alone, separated from the first formant by the nasal pole‐zero pair, again as the result of a nasalized articulation around /c/. For overtones with a frequency higher than 800 Hz, the overtone sound can be explained as a combination of the second and third formant as the result of a careful, retroflex, and rounded articulation from /c/, via schwa /E/ to /y/ and /i/ for the highest overtones. The results indicate a firm and relatively long closure of the glottis during overtone phonation. The corresponding short open duration of the glottis introduces a glottal formant that may enhance the amplitude of the intended overtone. Perception experiments showed that listeners categorized the overtone sounds differently from normally sung vowels, which possibly has its basis in an independent perception of the small bandwidth of the resonance underlying the overtone. Their verbal judgments were in agreement with the presented phonetic‐acoustic explanation.

Sundry Sounds produced by Leonardo Fuks and other examples

VVM phonation mode, physical model (by L.Fuks)

This is a simplified physical model proposed by me for the larynx during VVM phonation mode, which produces similar sounds to those from the Tibetan Chant tradition. Below, the vocal folds (m1,m2) and above, the false or ventricular folds (m3). In this example, vocal folds oscillate at a frequency which is twice as that of the ventricular folds. The letters m stand for mass, k for stiffness, and r for damping coefficient. Indexes r-l stand for left and right sides, respectively.

Sundry Sounds produced by Leonardo Fuks and other examples

During my research work in music acoustics I created/recorded/processed some gigabytes of sound files, most of them of no musical interest for the listener.
However, a few of them might be listened by tolerant and attentive ears. They are presented below.
The first group of sound files refers to Paper VI of my thesis, which are identified with the Tibetan Chant voice, and other extended vocal effects investigated in the paper.


Vocal-ventricular sounds (used in Tibetan and Mongolian “undertone” singing):
0.Original sounds from the Gyuto Monastery, Tibet

1.Fixed fundamental and sweeping overtones
2.f0/2 and f0/3 VVM
3. An imitation of a Tibetan Chant context (rather similar to 0, above)

4. Popeye the Saylor used VVM !! (an original recording from a William Costello’s version)
5. VVM and flute improvisation
6. Overtone singing in VVM mode, melody of “Oh, Susanah” (see the spectrogram)

Periodic pulse register , see Paper VI
7. Alternation between pulse register (“fry”) and modal voice
8. “Vocal fry” at fo/1,fo/2, fo/3, f0/4, fo/5 & back to 1

Vocal Growl (co-oscillation of vocal folds and epiglottis)-similar to the mechanism used by Louis Armstrong

9. Periodic Growl, in f0/2 and fo/3, with overtone singing

Tarogato (wooden saxophone from Hungary)
10.Tarogato(from the theme of Ravel’s La Valse)

A piece for OBOE called “My Six Marigaux 10499’s”, recorded in 6 channels

All recordings, excepted by numbers 0 (Gyuto Monks, Tibet) and 4 (Popeye, W. Costello) are performed by Leonardo Fuks

To the THESIS INTRODUCTION – FROM AIR TO MUSIC: Acoustical, Physiological and Perceptual Aspects of Reed Wind Instrument Playing and Vocal-Ventricular Fold Phonation

HTML by Leonardo Fuks

Last update 98.12.30

Overtone Analyzer – Demonstration von Stimmfunktionen

Overtone Analyzer – Demonstration von Stimmfunktionen

Published on Jun 17, 2012

Der Overtone Analyzer von bekommt demnächst Filterfunktionen. Hier schonmal ein kurzer Einblick, wie man mit den Filtern z. B. Stimmfunktionen veranschaulichen kann. (Die Filterfunktion ist derzeit noch ein Prototyp, z. B. wird das Knacken beim Loop später nicht mehr sein).

Comparing sounds with Overtone Analyzer (Part 2)

Comparing sounds with Overtone Analyzer (Part 2)

Published on Aug 14, 2013

Comparing sounds and audio recordings with Overtone Analyzer Premium. This tutorial shows the Long Term Average Spectrum (LTAS), and how to display the LTAS of several marked sections on top of each other so that they can easily be compared. The video also shows the Normalized Spectrum, which allows to analyze the relative harmonic intensity of a recording. These features are only available in Overtone Analyzer Premium, not in the Live or Free Edition. More about Overtone Analyzer at

Comparing sounds with Overtone Analyzer (Part 1)

Comparing sounds with Overtone Analyzer (Part 1)

Published on Aug 14, 2013

This tutorial shows how to compare audio recordings with the sound visualization software “Overtone Analyzer”. It explains how to mark sections of interest, and how to copy them to a new file, and how to display several files side-by-side for easy comparison. This tutorial applies to “Overtone Analyzer Live”, but it can also be followed with the Premium Edition. More about Overtone Analyzer at

Overtone Analyzer Quickstart Tutorial: record and visualize your voice

Overtone Analyzer Quickstart Tutorial: record and visualize your voice

Published on Mar 10, 2013

This video was made for Overtone Analyzer Live 4.0. The software has now been renamed into VoceVista Video 5.0. You can find an overview of all editions of the software at This is a video version of the quickstart tutorial for Overtone Analyzer that can be found at The video explains the basic features of the software and how to use them to record and visualize your voice or instrument. In particular, I’m showing you to set up your microphone, how to make a recording, how to play it back and listen to it, how to visualize the fundamental pitch, the spectrum, and the spectrogram, how to apply frequency filters to listen to individual overtones, and how to use the overtone sliders. Contents: 00:00 Introduction 00:17 Applying the Quickstart Profile 00:49 Select microphone and set input volume 02:20 Start recording, play tone on piano keyboard and sing it 03:14 Zoom and scroll frequency range and time range 04:52 Long-term view and short-term view 05:55 Replay a selection 07:07 Spectrum and Spectrogram 08:36 Frequency Filter 10:46 Overtone Slider 11:57 Conclusion

Sygyt Software: maker of Overtone Analyzer and VoceVista Video

Now available: VoceVista Video Pro 5.1.0

What’s new

VoceVista Video

VoceVista Video is a software application for the interactive recording and exploration of sounds. The visual display of a sound enables the quick recognition of the fundamental melody, the sound color (timbre) and the overtones. It also makes it easy to visually compare audio files.
VoceVista Video is particularly suited as a feedback tool to practice singing, and to document vocal development over the course of a voice education or therapy. Learn more

Voice Education / Therapy

  • Record voice lessons
  • Explain vocal phenomena
  • Create and repeat exercises
  • Document progress of vocal development

Singing teachers and students

  • Visual feedback through display of singer’s formant, vocal onset, timbre, vibrato
  • Practice intervals and melodies, monitor pitch
  • Study and teach overtone singing

Instrument builders / singing bowl makers and vendors

  • very precise frequency measurement, even for instruments such as singing bowls that have several independent tones
  • Measure planetary tones and other tonal systems
  • Document sound characteristics

Musicians and Music Teachers

  • Visualize the relationship between physics of sound and perception of music
  • Transcribe musical recordings
  • Assign and reproduce harmonic intervals as teaching- and composition aid