Glass Tap

How it's made

Source

a fingernail or small hard tip tapping the rim of a thin glass. Contact is a 0.3–1 ms broadband tick, band-limited above ~2 kHz so it reads as a crisp "tick" rather than a thud.

Body

a thin glass shell rings in inharmonic modes (ratios ≈ 1 : 2.32 : 4.25 : 6.63 : 9.38 : 12.8). Low modes ring longest (about the `ring` time), upper modes die within 30–90 ms, so the strike is bright and the tail clear.

Shimmer

shells are never perfectly round, so each of the three lowest modes splits into a pair a few hertz apart; the pair beats slowly and gives the short shimmering tail (`shimmer`). A faint high band of detuned partials glints for the first 50 ms.

Envelope

attack under 0.3 ms; the fundamental falls 60 dB in about 0.15 s; the render is closed by a smooth fade at roughly 0.3–0.5 s.

Variation

`rng` mistunes every mode by up to ±0.5 % and varies the tick, so repeated taps differ subtly; `pitch` scales the glass size, `brightness` the upper-mode level and tick colour.

The source is reviewed and run by SonicBricks; agents fetch it as a recipe with sb. It is not published on this page.