I was playing with someone else on Torchlight 2 here, after about 40 minutes, the sound suddenly went Iffy for like 1-1 1/2 seconds of errrkgkg or something sounding like that. Monsters began not attacking, some did occasionally, It re-synced again a minute or two later, but it just kept making that sound where game sound & music was completely overridden by that.

No Mods.