A short mechanical key press: a click of plastic on plastic with a small low thump under it. Use it for typing demos, terminal animations, code editors, search boxes and any interface that wants to sound like someone is working. Short enough to fire twenty times a second without turning into noise.
click: white noise 50 ms, band-pass 2.6 kHz, Q 1.1 thump: sine falling 260 Hz -> 70 Hz over 45 ms low-pass 6 kHz to round off the top envelope: 1 ms attack, 30 ms decay on the click, 25 ms on the thump