How do I do this? (scripting)

[Solarn]

I'm starting a custom story and so far I managed to work every script-related problem out by studying the original maps' scripts, but this time I'm at a loss. I have an area which I want to trigger a script when the player enters it, that will play footstep sounds (I was thinking of step_walk_wood_squeaky) at certain points at certain intervals, to make it sound like someone is walking above the player. I placed the area and the points I want the footsteps at, but no matter how I try scripting it, nothing will be heard.

To elaborate, this is my ideal situation:
- Player enters area.
- Music starts (search_grunt).
- Grunt noises happen at a point above the player (amb_alert). Sanity loss also happens.
- At about 1.5 second intervals, five footsteps are heard from five points on the ceiling of the room, forming a line. It would be nice if a falling dust particle effect could be applied to each step as well.
- a bit after the last footstep, music ends.

Here's what actually happens:
- Player enters area.
- Music starts (search_grunt).
- Sanity loss happens.
- After a while, music ends.

Here are the map and the script file (disregard the lantern-and-tinderbox-giving script, that's just the example debug script from the wiki that I found useful for testing purposes). Please tell me what I need to do differently.