Singing bowl glossary: frequency, overtones and more

Definitions for the acoustic terms used across ANURAVA.

By ANURAVAPublished 14 September 2026Updated 14 September 2026AN-KB-A29

The short answer

Singing-bowl terminology becomes clearer when frequency, pitch, mode, fundamental, dominant frequency, partial, overtone, harmonic, resonance, beating, sustain, decay, cents and tuning reference are defined separately. The glossary should be ANURAVA’s canonical vocabulary so product pages, Sound Passports, knowledge articles and chatbot answers use the same terms consistently.

Acoustics / physicsMusical convention

How to use this glossary

Every entry is written to stand on its own when quoted, and each has a stable anchor so it can be linked directly — for example /knowledge/singing-bowl-glossary/#sustain. These are the definitions used across ANURAVA product pages, Sound Passports and the rest of the Knowledge Library; where an article and this page appear to disagree, this page is canonical.

Definitions

Amplitude #

The magnitude of a vibration, heard as loudness. Amplitude falls as a struck bowl decays; it is separate from frequency, which is how fast the bowl vibrates rather than how strongly.

Attack #

The onset of a sound in the first instants after excitation. A bowl struck with bare wood generally has a firmer, brighter attack than the same bowl struck through suede, because the contact conditions differ.

Beating #

A slow pulsing in loudness produced when two components of a sound lie close together in frequency. In singing bowls it commonly arises when a vibrational mode splits into two slightly different frequencies, often from small asymmetries in a hand-formed shell.

Cents #

A logarithmic unit of pitch difference. One semitone is 100 cents and one octave is 1,200 cents. Cents make small tuning differences comparable across the range: cents offset = 1200 × log₂(measured frequency ÷ reference frequency).

Decay #

The fall in amplitude after the attack, as vibrational energy is lost to radiated sound, internal damping and the support the bowl rests on. Different partials in the same bowl can decay at different rates.

Dominant frequency #

The strongest spectral component in a specified analysis window. The dominant frequency need not be the fundamental: a bowl can radiate a higher partial more powerfully than its lowest mode, which is why a tuner may disagree with what a listener calls the pitch.

Fundamental frequency #

The lowest stable prominent modal frequency of a vibrating body. In the ANURAVA method it is identified from the settled portion of a standard strike recording rather than from the loudest instantaneous peak at the moment of impact.

Frequency #

The rate of a vibration, measured in hertz (Hz), where one hertz is one cycle per second. A singing bowl does not have a single frequency: it radiates a set of components, of which the fundamental is one.

Harmonic #

A partial whose frequency is an exact whole-number multiple of the fundamental. Strings and air columns produce near-harmonic series; the partials of a bowl generally do not, so calling every bowl partial a harmonic is inaccurate.

Hertz (Hz) #

The SI unit of frequency, equal to one cycle per second. 130.81 Hz means 130.81 complete vibration cycles every second.

Mode #

A specific pattern in which a structure prefers to vibrate, each with its own frequency and shape. A bowl is a vibrating shell with many modes; its geometry and material decide where those modes fall, and how it is excited decides which ones are strongly heard.

Note #

A named pitch class within a musical system, such as G3. A note is not a frequency until an octave and a tuning reference are stated: G3 is approximately 196.00 Hz at A4 = 440 Hz, and approximately 192.43 Hz at A4 = 432 Hz.

Octave #

The interval between one frequency and twice that frequency, spanning twelve semitones in equal temperament. C4 is exactly double C3 under any single reference.

Overtone #

Any component above the fundamental. Overtones are what listeners usually mean by the shimmer and complexity of a bowl. ‘Overtone’ does not imply a whole-number relationship to the fundamental — that stricter meaning belongs to harmonic.

Partial #

Any single frequency component of a complex sound, including the lowest one. Partial is the neutral, accurate term for bowl spectra, which is why ANURAVA records dominant partials rather than harmonics.

Pitch #

The perceived height of a sound. Pitch is a percepton, frequency is a measurement, and the two can diverge: a complex bowl spectrum may be heard as one pitch that does not correspond exactly to any single measured peak.

Resonance #

The tendency of a system to respond strongly at particular frequencies. A bowl rings because energy from a strike or from rim friction feeds its resonant modes, which then radiate as sound while they decay.

Rim playing #

Producing a continuous tone by moving a striker around the outside of the rim. The tone is sustained by a stick–slip friction interaction rather than by repeated impacts, which is why contact material, speed and pressure all change the result.

Spectrum #

The distribution of energy across frequency at an instant or over a window. A bowl spectrum typically shows several distinct peaks; reading it is how a fundamental and dominant partials are identified.

Spectrogram #

A plot of frequency against time with amplitude shown as intensity. A spectrogram shows what a single spectrum cannot: which partials persist, which fade quickly, and how the sound evolves as it decays.

Sustain #

How long a bowl keeps sounding after excitation. A sustain figure is only comparable when the method is stated — the strike, the support, the room and the decay threshold used to decide the sound has ended all change the number.

Tuning reference #

The frequency assigned to a reference note, from which every other note in the system is calculated. A4 = 440 Hz is the ISO standard; A4 = 432 Hz is an alternative reference, not a separate note or a property of an individual bowl.

Waveform #

The shape of a sound signal plotted against time. A waveform shows attack and overall decay clearly, but reveals little about which frequencies are present — that requires a spectrum or spectrogram.

Frequently asked

What does partial mean?

Any single frequency component of a complex sound, including the lowest one. It is the neutral, accurate term for bowl spectra, where components are generally not whole-number multiples of the fundamental.

What’s the difference between pitch and frequency?

Frequency is a physical measurement in hertz. Pitch is the perceived height of a sound. A complex bowl spectrum can be heard as a pitch that matches no single measured peak exactly.

Define singing-bowl acoustic terms.

The core set is frequency, pitch, note, mode, fundamental, dominant frequency, partial, overtone, harmonic, resonance, beating, sustain, decay, cents and tuning reference — each defined separately on this page.

Sources & methodology

Peer-reviewed acousticsTerwagne & Bush, ‘Tibetan singing bowls’Nonlinearity / MITModels bowl vibration from radius, height, wall thickness, stiffness and density; tapping excites multiple modes, rubbing preferentially excites one.
StandardISO 16: Acoustics — Standard tuning frequency (Standard musical pitch)International Organization for StandardizationSpecifies A in the treble stave at 440 Hz; confirmed current in 2022.
First-partyANURAVA Acoustic Method v1.0 and Sound Passport recordsANURAVAFirst-party measurement protocol and per-instrument documentation.

Written and reviewed by ANURAVA. Where a statement rests on a musical convention or a traditional association rather than on measurement, it is labelled as such in the text above.