How to silence npc

[cinderry]

Hi all, new to sound mods ... help, please?

 

I actually wish to create my own mod(s) to be able to silence (not bother changing) certain specific very irritating npcs (short of killing them :-)

 

One example is the preacher npc in Whiterun raving outside the Companions' palace - there are others (bards, maybe).

 

I've extracted the sounds.bsa to the desktop, so i am seeking a tutorial on how to find the sound file I want, and repace it with an identical, but silent, version.

 

Any help will be appreciated.