Solution found (although it's far from satisfying...)!

Tried to play an audio file from iTunes half-minded, forgetting that I have no audio - I surprised myself by actually hearing something...

Thanks for the response.

I tried this last night, and unfortunately, it had no effect, even after (supposedly) reinstalling the drivers. Yet, Realtek HD Audio isn't turning up in the device...

Audio devices (recording/playback) are not showing up in the sound menu. Even the generic 'speaker' is gone! Realtek audio also seems to have disappeared from my device manager, and will not reappear...