Were not talking about problems with sound, but video and the jerking freezes.
Sound can play an important role in how your game runs. Damaged audio files, problematic sound hardware, or improper CODEC's can cause game play issues; an add-on soundcard that uses a lot of CPU power to run, can interfere with a CPU intensive game such as Divinity 2. Especially if you have a dual core @3GHz or less.
That's why, as Raze stated, it's easy to go with on-board sound to see if thats part of the problem.
