soundscape_debug
... 
soundscape_debug is a console variable available in all 
Source games.
Soundscape_debug set to 1, displaying a few in-game soundscape entities in Portal, neither of them active.
A console variable that (when active) renders soundscape entities as purple cubes, each of them with a color-coded status line linking it to the camera.
It has three settings (0-2).
soundscape_debug 0- Off. Do not display any soundscape entities. (This is default.)
soundscape_debug 1- Displays all soundscape entities in the PVS.
soundscape_debug 2- Only display currently triggered soundscapes.
The status line is color-coded accordingly:
- Green - Currently being triggered.
- Yellow - Still active but not currently triggered.
- Red - Inactive.
