I have a switch that lowers a wall. I can do it and it works fine. I use a func_door. I can set the start sound and stop sound, no worries. However the wall is slow (by design) and takes a while to move. I'd like a scraping sound as it moves to supplement the start and stop sounds. How does one do that?

I could make a sound file that matches the time the wall takes to move, but what if I change the speed, then I have to redo that. Is there some way to tell it to play the sound while the func_door is opening, and then stop when it closes?

Thanks.

Set the func_door start and stop sounds.
Add an ambient_generic with the loop sound option checked.
Add outputs to the func_door to PlaySound for the ambient_generic.
(You might want to put a small delay on this output so that the func_door start sound does not overlap with the ambient_generic.)

From what little I understand of this stuff I think that should work for you.