One thing I think people missed is that our characters in oblivion don't seem to breathe. by that I mean, during a battle or sprinting, you don't hear heavy breathing caused by physical action. wouldn't it be more immersive if after running(as opposed to slow walking, which nobody ever does in game) after during battle you hear heavy breathing sound that fits into your action. for example, when you are swinging an axe, you are either holding your breath or exhaling, and after your swing you must adjust your breath; after your enemy is dead you are relaxed, and suddenly you are breathing heavily.

adding heart beating sound would be cool too... just not too loud lol.

I'm sure you'll hear some heavy breathing after sprinting. And maybe you hear you heart beat when your health gets really low.

YES!

we can also relate breathing and heartrate to fatigue level... if your fatigue level is low then you start to hear breathing sound.

I thought you were going to tell us to chill out, meditate or something. I'm sure we'll have breathing, and heartbeat noises. Audio is a really important element, and I think that's one of the greatest things that can pull you in. Have you played Daggerfall, do you remember the sound the skeletons make? Scares the living crap out of me.

For what it's worth, I do actually walk everywhere in-game.

OT: The breathing and heartbeating would be cool when appropriate, but I could take it or leave it.

in addition to the sound of breathing, we also need the shaking of hand (up and down) due to heavy breathing

There are mods (in oblivion) that add heavy breathing to the character when the fatigue is too low.

edit: it would be a nice addition, yes, but the sounds have to be bearable after you hear them 1000 times

There are some fatigue/immersion mods for Oblivion that add panting effects on low fatigue. It's pretty neat, but on the other hand what if you don't think that's how your character should sound? E.g the one I tried sounded like an old man wheezing.