Sorry, it will be long. I've been thinking a little about details (I do amaze myself sometimes

) and I've read a few things here and there on the forum, most of the ideas are about visual enhancement.
I remember that a guy in our team wasn't playing, simply standing at spawn point (was he eating, I don't know). I wasn't very far of the spawn point neither but when I heard "I'm taking fire" from that guy, I understood that an enemy was at our spawn point, right behind my back… and this call saved me.
I've read the dragonathan map idea (jungle/ruins themed), and I thought my anecdote could be applied here. You're in a jungle; there are many things you can hear, water moves, the wind in the leaves and various sorts of birds. Then imagine someone's moving and afraid birds, you might hear them flying, giving you information on players moves.
Of curse there are foot steps, fences hit and doors moves. But… Maybe could it be possible to adapt that kind of ideas to other maps. Like door alarms, splash sounds when you step in water puddle, barking dogs (I thought this sample was annoying, because looped and useless, but if it could tell me there's someone near
this fence, it would be helpful), doors chimes, metal detector…
I think (it's just my opinion) that we could gain immersive feeling if the maps were more "alive", responding to player actions in various ways (not simply sounds, might be lightening or moves). Until now, maps look like playgrounds, or massive sculptures. I don't feel like someone else used to live in there. (I do not try to complain, I really enjoy playing TC:E when I've got time, these are just ideas I've got -- and other people may have long time before I)
(thanks for reading, that was long, sorry again)