READ CHANGELOG FOR MOD EXPLANATION

WARNING!:
if the sounds don't work, you need to replace original sounds with the modded sounds ,Its The Sacrifice update's fault. As temporary solution I uploaded the pack so you could download it and replace the sounds, sorry for the inconvenience:

ATTENTION:
backup your left 4 dead 2 original sound file if you are going to replaced it with the modded sound file.

link for the modded sound file:
www(dot)megaupload(dot)com/?d=UP4QQTOR

type snd_rebuildaudiocache before creating a game, for the infected voice works properly
and the others are still the same.