http://homepage.ntlworld.com/gerald.mar ... akgerv.zip
Basically changes the sounds that were pretty weak in the game and replaces them with new ones (plasma rifle, pistol, machinegun). Chaingun now has to spin up for a second before firing and has new spinup\spindown sounds as well as an increased rate of fire and new firing sound, and 120 rounds instead of 60.
Or you can grab this version which has the ultrashadow mod, bodystay mod and the sounds in one pak.
http://homepage.ntlworld.com/gerald.mar ... akgerv.zip