I'm not an AMD user and it happens for me. I seem to only notice it when doing AOEs or in FATES or Dungeons where a lot of firepower is going off. Then it starts to stutter/echo and I have to turn the sound off. Happens in PVP too. Only place in game I've noticed it aside from those is at the Great Work inside the building with the steam.
It's still happening though cause it happened yesterday in the Blashphemies dungeon.