As far as the sound goes, do you have a audio cable running from your soundcard to the monitor? Because you NEED one in order to use the speakers that are built in to you monitor. The HDMI cables generally do carry sound but for a computer, a video card does not produce sound.
Also for video, I would just stick with DVI. From my experience, there is almost no difference in video quality when you use either DVI or HDMI.
Just as a side note: Monitor drivers are completely unnecessary (I wasn't even aware there existed drivers for monitors).