In the demo you could disable all voices by turning the "Voice" volume down to zero.
While I do not have the retail game myself, I would believe that there is an option to do this in the final version. Me? I would personally turn down the voice volume as soon as I started. I like my RPG's textual and my women... well... (the word is not textual, I'll tell you that <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />)
