If you go to the System Configuration > Sound > Equalizer and set the Equalizer to Standard, that usually brings it back but for many including myself the sound is not the same anymore. There's a huge sound bug happening that seems to occur in crowded areas or during fights that even after doing the fix I suggested will lack battle effect noises and voice acting in cutscenes... Soken tweeted that he was aware of the issue however, so hopefully they are actively working on a fix.