Cymatics Studio — 音を目で見る

The fundamental is the slowest, usually strongest vibration in a sound — the pitch you would sing back. We give it in hertz (cycles per second) and as the nearest note in three reference tunings: modern concert pitch (A = 440 Hz), the 432 tuning most of our chimes use, and the physicists’ “scientific pitch” (C = 256 Hz). Cents are hundredths of a semitone — trained ears start hearing a difference around 5–10 cents. The ± value is our measurement uncertainty: the shorter and noisier a recording, the less precisely any analyzer can pin a pitch down — so we show that limit instead of hiding it.

We compare your tone against four grids: the 440 and 432 note grids; Hans Cousto’s “cosmic octave” tones — orbital periods inverted to frequencies, then doubled octave by octave into hearing range (the arithmetic is real; the meaning people attach to it is a matter of belief); scientific pitch, a physics convention proposed by Joseph Sauveur in 1713, with C at powers of two; and the modern Solfeggio set — a 1990s numerological reading of a medieval hymn, not a historical scale. Octave-shifted matches are marked as such.

Almost no instrument makes a single frequency. Strings and air columns stack overtones at neat whole-number multiples — that is what “harmonic” means. Struck rods, bells, bowls and our pyramids follow other laws: their overtone ratios are a fingerprint of their shape. An exact 2.000× double with a suspiciously short ring can be playback distortion rather than a real overtone — when we see that, we flag it instead of celebrating it.

T60 is the time a tone needs to fade by 60 decibels — roughly “how long it audibly rings”. Q is the physicist’s version: how many swings the material manages before friction eats the energy. A guitar string lives around a Q of a few hundred; our crystal glass rods and pyramids measure in the tens of thousands — which is why a single strike carries for a minute or more. When a recording stops before the tone does, we extrapolate from the decay we can see and say so with a “≥”.

A slow pulse — wah… wah… wah… — means two almost-identical frequencies are taking turns. In a struck rod these are usually its two bending planes, a hair apart by geometry; the pulse rate equals their difference. It is not a flaw. It is physics you can hear.

Numbers are only as honest as the recording behind them. Compressed formats (mp3, m4a) and phone processing (auto-gain, noise suppression) flatten a tone’s natural decay, which biases ring-time and Q. For serious decay numbers: record raw, in a quiet room, and let the tone ring out completely.