The short answer
The fundamental and the dominant frequency need not mean the same thing. ANURAVA should define fundamental operationally as the lowest stable prominent modal component found by its method, while dominant frequency means the strongest spectral component in a specified analysis window. Reporting both prevents a complex bowl spectrum from being reduced misleadingly to a single number.
Measured by ANURAVAAcoustics / physics
Two different questions
Acoustics / physics
“What is the lowest frequency this bowl sustains?” and “which frequency is loudest?” are separate questions with separate answers. In a harmonic instrument they usually coincide. In an inharmonic shell like a bowl they frequently do not, because a higher mode can radiate more efficiently than the lowest one.
Why your tuner may disagree with your ear
Most tuners report the strongest component they can find in a short window. If a bowl’s dominant partial sits well above its lowest mode, the tuner reports the partial while the listener perceives a pitch closer to the fundamental. Neither is faulty — they are answering different questions, and the disagreement is diagnostic rather than an error.
Why the analysis window matters
Measured by ANURAVA
The strongest component at the instant of impact is often not the strongest a second later, because upper partials usually decay faster. Taking the largest instantaneous peak at the strike therefore tends to overstate the upper partials. The ANURAVA method analyses a window after the initial transient has passed, so the figure describes what the bowl sustains rather than how it was hit.
Reporting both
The measurement record stores a fundamental and a dominant frequency as separate fields, along with the strongest persistent partials. Where the spectrum is genuinely ambiguous, the field is left blank or a confidence level is published, rather than choosing a number to fill the gap.
Frequently asked
Is fundamental the loudest frequency?
Not necessarily. The fundamental is the lowest stable prominent component; the dominant frequency is the strongest one in a given window. In bowls these are often different.
What is dominant frequency?
The strongest spectral component within a specified analysis window. It only means something alongside the window it was measured in, because the balance between partials changes as the sound decays.
Why does my tuner show a different frequency?
Tuners usually report the strongest component, which in a bowl may be a partial above the fundamental rather than the fundamental itself.
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.
- 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.