I have to agree to one point and add one more:
-Suppressors are useless on ranges of 25 meters or more.
You can't hear gunfire on distances over 25 meters.
I often hear bullets land near me without hearing gunfire.
Then I die.
A suppressed weapon, I think.
But watching the killcam -- my killer fires a LOUD LMG at me for SECONDS before he hits and kills me.
Better hear EVERY gun fired EVERYWHERE on the map, than not hearing the gun that fires on YOU from 30 meters.
-Footsteps are not there.
You need a perk to hear enemy footsteps.
(Be careful with BOTH awareness and dead silence; Don't make dead silence make players inaudible, and don't make awareness make players sound like elephants. A subtle 0.5x sound for dead silence and 1.5x sound for awareness is more than enough. Then awareness cancels out dead silence up to 1.0.)
We have crouch and walk functions for a reason.