Right now, I'm watching Scumps stream and the sound completely changed. You are not alone! It's like you are wearing a helmet and the sound is muffled. The sound is not 'open' as it was in the Alpha.
The game is also over bassy to the point you have this wub-wub feeling going on all the time. I appreciate Treyarch trying to change these things, but the game isn't pleasing to hear at all. It's all over the place and straining.
The alpha was perfect. Sure the gun sounds needed a little tiny bit more punch and the steps needed some range adjustments, but the general direction was good!
Have you tried using any of the audio presets we have in our beta? Try giving High Boost a shot and let me know how you feel about it.