Was questing in Frostgorge Sound before the March 31st patch and had no issue. The day of the patch, I updated my client and when I logged into the game and starting playing, I noticed that the footstep sounds on my Ranger would cut off randomly when moving around ,  about every 15-30 seconds. All other sounds work (music, weapon sounds, etc… )
After some testing, it seems to happen in areas with alot of activity. I found a  quiet spot with no mobs, quests,  and ran around for 10 minutes and the footstep sounds never cut off. As soon as a enter a busy area with npcs, mobs, hearts, etc… it begins to happen sporadically.
Messed around with audio settings in game, in Windows 7, nothing helped. I tested a dozen  other games on my PC. None of them have this issue.