You’re surrounded by zombies on all sides, but they don’t see you yet. You’re sneaking through the abandoned stalls of a grocery store. Then, clumsily, you bang against the metal shelving, producing a notable sound… which the zombies ignore. Then you do it again. Then you knock the shelf over. Then you walk up to a zombie and scream at it, and the darn thing still doesn’t notice that you’re there. The point we’re getting at here is that having the zombies (and wildlife) in H1Z1: Just Survive be more responsive to sound is a good thing for tension.
Not only will zombies be a fair bit quicker about shuffling over to check out noises, but there are going to be more of them; zombie density and upper limits have been increased per player, meaning that you can find far more zombies around to run from. Firing from the hip has also gotten less accurate, so you’ll have a harder time shooting down the zombie hordes. It can be frustrating, but it will be better than screaming at a zombie who doesn’t even notice you’re there.