Still waiting to hear back from them…
Chances are terrific you will wait forever. ACX is not in the business of adjusting your studio.
hiss / whine from my laptop’s wheezy fan
Can you tell that your computer is on just by listening? Kiss of death. If you can tell if your refrigerator is on just by listening, that’s not good news, either.
that happens from time to time.
It’s not always noisy? Maybe that was their real objection. They hate chapters that don’t match.
ACX Check will only tell you if your work meets technical standards. The passage has to be comfortable. Noise should come in around -63dB to -65dB. Not -60.5dB. Particularly if your noise is irritating to the ear, you will have to do better than just squeak past.
When your work goes to ACX, it also has to pass Human Quality Control where they judge you on your reading ability. Nobody wrote you can’t have two or more problems. They will only report the worst or first failure. See: They’re not in the business of fixing your studio.
Your recording room has to be dead quiet. My little third bedroom is very quiet and but I still have to wait for the Los Angeles Metrobus to go by before I start reading. VROOOOOM!
Record and post a sound sample according to this formula. Do not adjust anything. Record, export and post.
http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html
Go down the blue links. They’re very short and they will give you hints how to complete each step.
There is a way around the noisy computer thing. Stop using the computer. This is a Zoom H1n stand-alone sound recorder.

That’s my photo studio. Replace all the wood with my quiet but non-photogenic third bedroom.
People have used Zoom H4n and Zoom H5n. Other people such as Tascam make good recorders. National Public Radio used to use Tascams for their field recordings. They may still. The H2 and H5 can use external microphones.
There are ways to quiet down a small room, too. This is a kitchen table sound studio.
https://forum.audacityteam.org/t/too-compressed-rejection/52825/22
Koz