Timers are essential tools. We need them for a variety of reasons--- to play sounds or make particles at specified intervals, to time out blue menus, to stop prims from listening (and save server resources), or to pace changes in a prim's position or characteristics.
It's possible to use multiple timers (and I will eventually write about this), but for now, here's an annotated script that will play a click sound at a specified interval after the prim has been touched.
//----- Cut the text below and paste it into a script in your prim in Second Life
// Simple Timer by Cheyenne Palisades
float interval = 3.5
// a float is a variable; set this one to set your timer's interval in seconds
// do the following when prim is touched
// Plays double click sound when prim is touched
// The numbers in quotes are the UUID of the sound
// The last number is the volume; you can set it from 0 (silent) to 1 (loudest)
// Now the timer is set to (interval) seconds, 3.5 if you haven't changed the first line of this script
// Plays double click every (interval) seconds after prim has been touched. This will continue indefinitely or until timer is set to 0
// You can substitute your own sound by replacindg the UUIDs above-- or drop the sound into your prim and replace the UUID with the name of the sound. Sound will fail if UUIS or name is not exact.