I have never got the sound problem on default settings. That being said and my experience from other games with sound issues could be driver problems which either have to be corrected by a new driver or GW2 patch. For the four games I did have problems with sound it always happened at Highest Quality. The problems ranged from crashing, total loss of sound, feedback, or looped sound. I’m sure it will be corrected with patch since Creative don’t do much on there end.
i can confirm this as i have only had the problem when on highest quality. never any problem with it with anything lower.