: To be honest, I first tried to mentally recall all of the Pfhor ship maps.
: But not remembering every little nook and cranny, I fired up M1 and
: wandered around all of them using my dusty and aging saved games. It's
: interesting that this is the only occurrence of that sound. You'd think
: Bungie would have had other similar situations on all of the Pfhor ship
: maps.
They did. One other door and partly the premise for the whole level. But it is so easily overlooked once you are familiar with the level. At the very start of Two Times Two Equals, your back is to a locked alien door. Most of the level is designed around working your way to the other side to open the door. Not exactly the most stimulating of objectives.
If you are like me you probably fire up this level and head straight down the walkway without even looking behind you. But the door is locked, it makes an alien closed door sound, but not in M1A1.
So three occurrences. Rare in Marathon Sound terms.
But not as rare as that 'knocking' sound.
Cheers
Hamish