Anyone know how to change the NPC audio files?

I.E. I have Valygar, but don't like his sounds, so I wanna swap it with somethingelse. Or I'm tired of Aerie's voice, but wanna keep her, so I need to change the audio to something more bearable.

>>First Post!! :)

Save new WAV files into the override directory with the same filenames as the original soundfiles.

Is the audio suppose to read itself with the nps. My only does once in a while. Even when the just talking to each other and not to the pc. Just wondering?

where do you find the npc's original soundset?