Hey. Can someone help me out in getting a ticking clock noise going for a timed door? (I have the door and button working fine.) I don't know which entity to use to make the noise, or how. Are there any tutorials that anybody knows of that would help?

I'm not precisely sure you need, however, I think this might be some help. There is some information there about using ambient_generics which seem to be what you need to use for the right sound.

This isn't too hard. I'll throw a wiki up about it later tonight, until then here ya go:

Create an ambient_generic, and give it a name of ticking_sound
Set the Sound Name parameter to Portal.room1_TickTock You'll need to just type it in, as it is not in the the list if you hit browse since the SDK isn't updated yet.

Next create a logic_timer, name it tick_timer.
Set the Refire Interval to 1. Go to its outputs tab and add this output:
OnTimer -> ticking_sound -> PlaySound

Go to the func_door that is being timed and set these two outputs
OnOpen -> tick_timer -> Enable
OnClose -> tick_timer -> Disable

And you're good to go

And I didn't add that information into that wiki Hober since... well, I guess I didn't think many people would be putting those types of doors on timers in general. It's usually used for moving platforms and such... but like I said... I'll throw this together in a quick wiki tonight or tomorrow morning.

It should be noted that, thanks to Shmitz, using the sound alias name will mean that it will assume certain properties that can't be overwritten, such as maximum sound distance and volume. If you want more precise control over the sound and don't want it to be totally identical to the ones in-game, you'll have to use the /path/to/sound.wav in the Sound name.