I've been using the OMP 0.2 pack for years, and recently the newer ones in Unreal 227i
My general take on tinkering with the new renderers follows.
Unfortunately it's more of an art than a science.
The renderers can behave differently depending on your drivers.
Hardware and software mode tend to differ in volumes.
The main switches that affect the way you hear sounds at a distance are
UseOriginalUnreal and AmbientFactor
These new renderers have features such as bRayTraceReverb, bSoundAttenuate and bOcclusion.
They make sounds change in various ways depending on the room or environment you are in.
Most of my info is from the wiki (where it explains what the new switches do)
http://www.oldunreal.com/wiki/index.php?title=OpenALI'm testing the new SwFMOD as It has lots of new options to play with.
So far the bullet-sounds whizzing past my ears, with the Chaos mod in v451 are very cool.
Not sure if the footsteps and such count as ambient sounds, but try dropping the ambient volume low and see how much difference it makes.
UseOriginalUnreal will affect how you hear distant sounds, but I'd recommend swapping between HW and SW modes first, then try the others.
Quickest way to change the settings is by pressing TAB then typing "preferences".
If you have the Oldskool mod installed, it adds an "Advanced Options" to the UT menu.
If you don't have UT open, it can be quicker to access the "Advanced Options" from the view menu in UEd.
You can make immediate changes to the video renderers like this, but not the audio. Unfortunately UT needs a restart to try any changes.