Some stage questions (Sounds and triggerable events)

[ForOhFor Error]

1. is it possible to have triggerable events in a hacked stage (not texture hack, say an import)
Say, hit a switch, and a door opens?

2. Can you add sounds to stages (NOT music, sound at certain times, like the alarm in that parasite queen stage?)

thank you

~404

[The Corrupted one]

I do not think so I saw a hazard in a stage a while ago but I do not think it is easily done
Mabye refer to code from sse