I'm not sure if this is the right forum, since this involves Hammer AND the Puzzle Maker. Anyway I'm thinking of using the Puzzle Maker with Beemod to make future maps, then edit it further in Hammer. The thing is I don't want the PTI music, Cave Johnson PTI lines, or GLaDOS's "Hold on ho? I swear I know him. Oh I like this guy!" to play.

I tried setting the "Disable PTI audio" on the entrance elevator instance to "1" and "yes", but neither of those worked I still hear the music playing, I don't know if any of Cave's lines play since I've already heard them all.

I can find the choreo_sceenes & ambient_generics related to the sounds, but darned if I can find what triggers them! And I've looked at all the logic autos, logic relays and triggers I could find.

Nothing short of removing the choreo_sceenes, ambient_generics and the global_ents instance will stop the PTI music, in-game GaLDOS & Cave lines, (I did make a backup copy of the instances they were in) but I'm sure this is not the right way to do it as it's going to try to use things that are not there anymore. Strangely enough, any map I try this on does still seem to work.

What's the right way to do this?

Set Disable PTI Audio to 1 to silence Cave Johnson.

I don't know which entities control the music, but I know part of it is stored in the mandatory observation room.

Music's in global_ents which is inside the elevator entrance - it's named @music so you could just use a logic_auto or something to kill it before the player reaches the entry. There's quiet versions of the p2editor_clean instances - check there and switch to those versions, that will stop GLaDOS from speaking. They are triggered from a lot of instances, the outputs won't do any harm really.