[SCRIPT] FATAL ERROR: Could not load script file

[Mudbill]

Where do you want these sound effects? If you just want ambience stuff, here are some suggestions.

If you want for example critter noises in a certain room, add a script area there and use the PlaySoundAtEntity() function on it. Alternatively you can use the editor "Sound" object. Make sure you select a looping sound, or else it's likely not going to be noticed.

If you want a random wind or thunder sound play as the player walks by, add a script area with a collision callback for the player. In the callback, run a PlaySoundAtEntity() function. That function can be used to make the sound play from a certain source in the map. If you just need a sound that doesn't use 3D, you can use PlayGuiSound() but that's mostly for player gasp sounds and such.