I'm a returning Oblivion player. Reinstalled and having some minor sound problems

Game Software
Game of the Year Edition
Shivering Isles & Knights installed
Unofficial Oblivion Patch installed
OBMM installed
"A Takes All mod" installed (the first of several small gameplay mods I intend to install)


System Info
Windows 7 Ultimate
Sound card drivers are onboard cheapies I guess:
"High Definition Sound Card driver"
"SBG Audigy"

Drivers for both soundcards have been updated

When the game transitions from normal context view into NPC dialogues (Uriel Septim; his blades) no voices for the NPC dialogues. NPC voices and other sounds work otherwise, although there was a bit of sound distortion prior to installing UOP; haven't noticed if that fixed the more general issue.

I seem to recall that, with my old and now dead system I was told that a better sound card might noticeably improve my game performance as Oblivion is pretty high demand on sound?

Or perhaps, something is just not installed properly? Else I've failed to patch up to the final 'official' patch?