Ditto on North, some of it is mic discipline in the patrol cars (leaving them on the clip while talking). The primary cause in my opinion is just how hot the repeater is putting out audio, it's on the lower side based on the others in the county.
I could comment the same for Sussex county dispatch, depending on the dispatcher (perhaps the headset) the audio can be really low even when sending out a message after tones. All radios from scanner to my commercial radio (although it's audio does the best as you would expect from a M)