It's really hard to tell what needs to be changed (I'm not an audio engineer), but it's either the music level or the sound effects themselves that give me the impression that I'm fighting while having my ears stuffed with cotton. I think it's the latter. This has been true since E:WoM and is an unfortunate detriment to the game.

Example: Whereas casting, IIRC, Slow played a magical sound effect, Haste played no sound effect. Other effects seem to have that same isolated deadness and rip me from suspension of disbelief. Likewise hit/death sounds are short and have a similar deadness that is hard to pin down.

Bedwyr