Time to throw my hat in the ring:
I'm having audio popping issues, but it's almost exclusively in dungeons and trials, and like pretty much everyone else has only started with the release of 6.0. The 6.01 patch did absolutely nothing, and I am having no audio issues with any other game.
It was bearable until the lv89 dungeon, and then got REALLY bad during the second trial, which is extremely disappointing because it obliterated the atmosphere and made it impossible to listen to the music.
It isn't just EW content that's been affected; I've also noticed audio popping in a few other situations, Thornmarch was bad for example.