A single tick from a small mechanical clock: a dry escapement click with a tiny brass ring after it. Use it for countdowns, timers, suspense, metronomes, or a scene where time passing should be audible and slightly unfriendly. Short enough to repeat once a second without the ticks smearing into each other.
escapement: white noise 8 ms, band-pass 3.1 kHz, Q 2.4, then high-pass 900 Hz brass ring: sine 1860 Hz at 14 ms, 120 ms long, 2 ms attack, 22 ms time constant (it follows the click by 6 ms, so it reads as one tick and not two; down to about -44 dB by the time it is cut) body: sine 380 Hz -> 240 Hz over 30 ms (140 Hz of drop on top of a 240 Hz floor), at 30% level low-pass 9 kHz envelope: 0.5 ms attack (a hard click), 7 ms decay on the noise