Suggestions for soundproofing and background elemination

There appear to be two different version of rms normalize that you’ve posted on the forums. This one, released in Dec. 2015 as well as this one, released Mar 2017. The Mar 2017 version is the one linked for download from koz’s Audiobook Mastering.

Here’s a (zoomed-out) comparison of the code, with the 2015 version on the left: