Overtone Singing

Central Asian khoomei and khöömii

Khoomei, also spelled khöömei, is a form of throat singing described as originating in the republic of Tuva in central Asia. Mongolia's Khöömei was inscribed on UNESCO's Representative List of the Intangible Cultural Heritage of Humanity in 2010. The nomination describes it as a practice of the Altai mountains in western Mongolia, believed to have been learned from birds, which are central to shamanic practice. Mongolian nomads perform it at occasions from state ceremonies to household celebrations, while herding, and to lull babies to sleep.

The UNESCO page says Khöömei is traditionally passed on orally from bearer to learner, often through a master-apprentice relationship. The sources reviewed give no firm dates for when the technique began.

Tibetan Buddhist harmonic chant

A university magazine report describes the harmonic chanting of the Gyuto monks, who have lived in exile from Tibet since the 1950s. According to the report, the American religious studies scholar Huston Smith recorded the chanting at the Dharamsala monastery in India in 1967, and the monks meditate on the sound as an embodiment of emptiness. A musicologist quoted in the report calls the ritual 600 years old, and says novice monks begin training at about age 10 and spend five years memorizing 2,500 pages of text before learning the harmonic chant.

Inuit vocal games as a separate tradition

The Canadian Encyclopedia entry on Inuit vocal games states that the origin of these games is unknown because the Inuit kept no written records, though explorers and missionaries documented them in Alaska and the Canadian Arctic in the nineteenth century. Christian missionaries banned them as non-Christian practices, and a resurgence began in the 1980s among elders and youth. In 2001 the Avataq Cultural Institute hosted a conference in Puvirnituq, Nunavik, of 100 Inuit throat singers to begin a movement to preserve the games. This is a distinct tradition and is not the same as Central Asian or Tibetan overtone singing.

Scientific description from the 1990s

Journal papers in the early 1990s described overtone singing as a technique of Asian origin and analyzed its acoustics. A 1992 paper gave an acoustic and perceptual analysis, and a 1993 paper described the production of an enhanced harmonic over a fundamental in a trained singer. Later papers on Mongolian, Tuvan and Inner Mongolian singers are discussed under Research and Evidence.

Overtone singing and harmonic singing

A 1993 voice-science paper defines overtone singing as one person singing in two voices: the first voice is the fundamental, and the second is an enhanced harmonic. A 2021 case study describes a low, continuous drone with a melody played on the higher, flutelike, strongly enhanced overtones. The terms overtone singing and harmonic singing are used for this effect, and biphonic or diphonic singing refers to the two pitches heard at once.

Names within Central Asian traditions

Names differ by place and style. The UNESCO nomination for Mongolian Khöömei names two main styles: kharkhiraa (deep Khöömei), with emphasis on a sub-harmonic an octave below the drone, and isgeree (whistled Khöömei). A study of Tuvan singers used the sygyt style. A Mongolian bass-type style is called Kargyraa in Mongolia, in a 2001 voice-source study. A study of Inner Mongolian singers in China asked them to sing 18 types of Hoomei, and an earlier study of one performer in China distinguished vibration, whistle and overtone höömii.

Katajjaq and the broader term throat singing

The Canadian Encyclopedia notes that non-Indigenous people first called Inuit vocal games guttural songs or throat songs, and that ethnomusicologists later preferred throat games. The Inuit term katajjaq applies only to Arctic Quebec and the south of Baffin Island, and the author suggests the neutral term vocal game for the wider family. The phrase throat singing is also used in voice science for other practices that involve the ventricular folds, including rock and metal vocal distortion, so the phrase on its own does not identify one tradition.

How two pitches are heard

In an eLife study of Tuvan singers, the authors report that the biphonic sound combines the fundamental pitch with a focused filter state at a higher pitch (1 to 2 kilohertz) formed by merging two formants. They conclude that the effect arises from linear filtering of the vocal tract rather than from a nonlinear sound source. The sample was small: three singers in the sygyt style, one in a non-sygyt style, and MRI data from one singer.

A 2021 case study of one overtone singer found the enhancement came from close clustering of formants 2 and 3, and that tongue shape changed from a raised, retracted tongue tip to a dorsal, posterior articulation as the overtone rose. The authors say this type of overtone singing is explained by source-filter theory. An earlier analysis found that tuning a formant and narrowing its bandwidth makes a harmonic prominent.

Vocal tract and laryngeal observations

A dynamic MRI study of one male overtone singer compared three overtone techniques and found that each relates to a specific conformation of tongue, lips and palate. Studies of the Mongolian bass-type style found that the ventricular (false) folds vibrated at half the frequency of the true vocal folds in one male singer, and that vibration and overtone höömii in one performer in China involved the ventricular and vocal folds acting together as a double sound source.

A 2025 study of Inner Mongolian Hoomei singers reported that contact of the false vocal folds and narrowing of the posterior vocal tract are both important for some styles. A 2026 aerodynamic study of one trained male singer, using Kargyraa and mixed distortion rather than overtone melody, measured higher airflow, higher pressure and 2 to 6 dB greater intensity than modal voice.

Tibetan low chant

The ANU Reporter article describes the Gyuto fundamental as extremely low, at the octave of a double bass, which makes the harmonic content easier to hear. Its musicologist reports a case study of one chant master in which the harmonic voice had more high-frequency content than the normal voice. The article notes that the sacred nature of the tradition limits what can be published about how the sound is made, and this page does not describe technique.

Uses within the source traditions

Within the traditions described above, the sources report uses that are social, ritual and meditative rather than medical. UNESCO lists ceremonies, household celebrations, herding and lullabies for Khöömei. The Gyuto monks are reported to meditate on the sound as embodying emptiness. Of katajjaq, the Canadian Encyclopedia reports it was done for pleasure, to put babies to sleep, on returning from the hunt, and as respiratory training in bad weather, adding that some argue it once had a shamanistic function, and that it is first of all a competitive game.

Use in contemporary sound-based settings

Practitioners of sound healing and vocal toning describe overtone singing as a way to relax, focus attention or deepen meditation, but the sources reviewed do not document these claims. The discussion section of a 2025 magnetoencephalography (MEG) study suggests that overtone-rich stimulation may offer a low-threshold means of relaxed and internalized states, and the authors call for future studies to test this.

A short French-language article by a singing teacher describes overtone singing as a relationship tool in work with infants and adolescents and calls it overtone singing therapy. It is a practitioner commentary, not a study, and only its abstract was read.

Voice science and acoustics

Most of the research found concerns how the sound is produced: acoustic analyses, MRI, laryngoscopy and high-speed imaging of the larynx. Samples are small. Several studies examined a single singer, and the Tuvan study had four. Singers were mostly men and often professional performers or teachers. These studies describe mechanisms and do not measure effects on health.

Brain and perception

A 2025 MEG study of 17 experienced overtone singers recorded brain activity while they heard sung syllables ranging from speech-like to overtone singing. Theta-band power rose as speech content fell, with right-hemisphere lateralization, and overtone listeners showed higher theta and lower gamma power. The authors describe the findings as exploratory. Two authors are affiliated with an overtone singing school, and the study did not test stress, mood or health outcomes.

Wellbeing, stress and mood

No randomized trial, controlled study or systematic review of overtone singing for stress, anxiety, mood or other health outcomes was found. PubMed searches run on 2026-10-17 combined overtone singing, throat singing, khoomei, harmonic singing and Tibetan chant with terms such as trial, anxiety, relaxation, heart rate variability and EEG. They returned acoustics, laryngeal physiology and perception papers, not intervention studies. Research on other chanting or on singing bowls does not show effects for this technique and is not summarized here.

Voice strain

No study reviewed measured injury from overtone singing as practiced for wellbeing. A cross-sectional survey of 300 Tibetan monks in a monastery in India found that 39 percent reported voice problems during their careers, most often hoarseness, sudden voice change and dryness. Risk factors included more than 8 hours of daily prayer, praying with musical instruments, not sipping water between prayers, and acid reflux. The survey concerned prayer and chanting in general, not the harmonic chant specifically.

The 2026 airflow study found higher airflow and pressure in Kargyraa and mixed distortion in one singer, and the introduction of that paper states that some singers produce these styles without reported discomfort. The data do not show whether strain results, and the findings are from one singer.

Breathing and care boundaries

The Canadian Encyclopedia notes that an Inuit vocal game stops when a player runs out of breath or laughs, and that rising and dropping on the heels makes the game more breathless. The sources reviewed do not report studies of hyperventilation or lightheadedness in overtone singing, so this page makes no claim either way. Persistent hoarseness, pain or voice loss warrants assessment by a clinician, and singing practice is not a substitute for necessary medical care.

Restricted knowledge and attribution

The musicologist quoted in the ANU Reporter says his access to the Gyuto monks' sacred tradition is limited. Outsiders are offered an essence of the chant and not full understanding, in part because the texts are described as spiritually powerful, and in part to keep a long ritual unbroken. He says he would dislike being partly responsible for a non-spiritual version of the chant. For this reason the page gives no instructions for sacred chant.

The Canadian Encyclopedia entry says that recordings and interest from outsiders have created a distortion of the true place of Inuit vocal games, since the drum dance is the predominant Inuit musical genre and the vocal games are one game among others. Readers who learn these sounds can credit the specific tradition, such as Tuvan, Mongolian, Tibetan or Inuit, rather than treat them as interchangeable.

Learning and transmission

The sources describe traditional learning as oral and relational. UNESCO describes bearer-to-learner transmission for Khöömei, and the ANU Reporter says that a monk may be shown quickly and then learn by being part of the group, with no textbook for a western audience. Two papers in the evidence base have authors affiliated with overtone singing schools in Germany and Italy. The sources reviewed identify no accredited training standard, professional register or regulated title for overtone singing teachers, and none was searched for beyond these sources.