Would it be possible to have some plaster fall off the wall instead?
In the silo. If you’re outside the silo, it wouldn’t hear your footsteps, but it most definitely would hear gunshots.
@Raminator: Couldn’t you have pre-made sections of the wall that are dented and misshapen, as if they were hit by a tentacle, and have those ‘switched off’ (aka invisible and with no collision), and when you fire a weapon near that section of wall (in a scripted trigger zone), the ‘good’ section of wall is ‘turned off’ and the bent and destroyed section is turned on, and the transformation is masked by loud noises and particle effects? I mean, I edit a 5 year old game (jedi academy, runs on q3 engine), and what I just described would be exactly what I would do to make an event like that happen. I’m positive source has the ability to do these things. It would be a simple scripted event wherein if the player fires his weapon in a triggered zone near the section of wall to be transformed, two premade wall sections (in my game they would be func_usables. they switch on and off in the game world when used.) switch places and a particle emitter is turned on, and a sound is made. Simple. No vast computations required.
I hate to be a dick and tell you how to do your job, so to speak, but I think this is a reasonable solution, and I’m not speaking out of my ass. If a 5 year old game running on q3 can do what I described, then I’m sure source can.
Another idea down the drain.
NEXT!
Damnit, it was such a cool idea. 
That’s really unfortunate. Well at least that tells me that you have lots of other neat things going on in that map, which excites me. 
And what about debris falling from the roof, when you are in these hallways? Wouldn’t that be cheap, but do the job right? You hear a bang, the camera goes earthquake-style (just as it happened with the Gargantuas) and a few rocks fall from the top.
That already happened in HL1.
^ True
Really?
Except that would be weird since the silo walls are metal and not plaster, hence the rust.
Yeah, but they were scripted and there was no connection between any action the player did and the metal falling. Even if you crept around the entire map and the tentacle wasn’t even aware you were there it would still collapse. What he’s suggesting is that, instead of dents appearing in the wall, small bits of debris would fall from the ceiling to show some sort of correlation between the player making lots of noise and the tentacle trying to break through.
I think it’s a good idea, but slightly flawed. Firstly, if you’re talking about small bits of debris, how would this be plausibly shown? It’s not as though the entire area is made up of small girders or railings that would neatly form debris - the silo is made up of incredibly large bits of metal that, when dislodged, fall with devastating effect (as shown). Secondly, there’s the question of whether they should cause damage or not. And thirdly you have to take into account how taxing this is all going to be.
A possible solution would simply be to have dust falling from the walls and ceiling. It’s cheap, dispensible, resuable and, when not overused, can look great.
@Ram - couldn’t you simply have a scripted sequence of a tentacle denting the silo wall? If you’re taking into account the possibility of a player crawling around and being quiet (and where a tentacle attacking the wall would be obviously scripted therefore), you could have it occur when a large piece of debris comes crashing down - the louder the sound, the more frenzied the tentacle will be when it attacks the wall.
How would it be frustrating and add nothing to gameplay? I’m not talking about the tentacle’s head constantly being in the room - it would only come in when the player makes a loud enough sound. Or perhaps it would just be scripted.
Aside from that, it’s a flaw in the existing design. Why, when the tentacle has evidently got into the room with a lot of force and dragged a scientist out by the waist, would it not do it again?
I think instead of gibbing that security guard that starts shooting at the tentacle, it should impale him and drag him back into it’s hole.
Really? It’s been too long that I played HL, I thought it was made of concrete :fffuuu:
Yeah, that would be sweet. 
I think it’d be even better if the player was sneaking at the time, believing he was invisible to the creature then BANG! Fucking girder lands 2 feet away.
!OMG!HOLY cow! I just jumped in my seat just reading that suggestion! wub it. absolutly wub it.
That would be pretty awesome actually.
Yeah, then they just turn and look at you and you’re all “shit shit shit shit shit shit shit shit shit shit…” Then you either get splatto’d or throw a grenade and save yourself.
What are you talking about? What I’m suggesting takes place in the corridors outside the rocket chamber.