I just submitted my first audio book to ACX. According to ACX, the book is 54 minutes shorter than Audacity says it is. [ACX 8 hours, 22 minutes; Audacity 9 hours, 11 minutes.]
Is this normal?
That one’s new. So I can make an MP3 play at the wrong speed by starting out at 48000 rather than 44100? I bet that’s not enough of a speed shift to trigger any QC errors.
Koz
My bad. I re-did it and it came up pretty close timewise --addition has always been such a toughee for me. 
BTW, when I uploaded it, it instantly said that I had “met all Submission Requirements” and that they were now sending it to their “Quality Assurance” people, so I’m hoping that means it got past the technical stuff.
I had a lot of fun doing this with Audacity, and I have no complaints. But, in case you are interested in where the problems were, I did get some blips and boops, examples below. Again, no complaints! And thanks again for that Notch Filter taking out the air conditioning hum.
distortion on removed.aup (1.01 KB)
distortion on Jeremy.aup (1.16 KB)
crackles on and your grandfather.aup (1.02 KB)
met all Submission Requirements
That’s the robot. It works in a similar way to our ACX Check program. Also, I bet they can tell other specifications such as file sizes, lengths of presentation, etc., completely automatically. Billions of people submit sound tests every ten minutes and they need a quick way to winnow them down.
The next level I call Human Quality Control. That’s when somebody with a pulse listens to it and that’s where you die if your sound quality is trash (difficult to tell automatically) or there’s some other theatrical damage.
So if you’re reasonably careful with breathing and “wet mouth noises” (I love that phrase), you should be well on your way to publication.
The AUP files are cool, but they are Audacity Project Manager text files, not sound. You can post mono WAV samples up to about 20 seconds or MP3 samples longer. Don’t go over 2MB.
Koz
Oh, sorry, forgot. Been a while.
That’s unfortunate.
I found two glitches (of the many).
Those sharp vertical transitions are places where the computer stopped following the show. If they’re big enough, they sound like a tick or pop and they’re pretty common. The solution nobody wants to hear is stop using the computer. If you do need to keep using it, production is going to get a lot more interesting.
There are tools to help with pops in post-production—the vinyl record people have tools to help with car hairs and other record noises and there are versions for this problem. None of them are particularly thorough and you’ll need to go through the show carefully, manually, and make sure you got all the ticks.
Preventing the machine from making them in the first place involves concentrating the machine’s attention on you and nothing else. No other apps running. There can also be storage/hard drive and internal speed problems contributing to the damage as well.
Nobody wrote you can’t have more than one problem.
https://manual.audacityteam.org/man/faq_recording_troubleshooting.html#skips
Stand-alone, dedicated sound recorders don’t do this.
Koz
It’s not that big a deal, I just re-record the sentence and paste it in. Cost of doing business kinda. 
Cost of doing business kinda.
Can you get it down to a time and place the machine does that? Something you can prevent?
Koz
No, it just happens when it happens, I don’t see any rhyme or reason to it. It doesn’t bother me, I have to re-record plenty of other stuff when I do my blooper-corrections, so having to do a few more re-recordings due to mysterious clicks and crackles is no big deal.
BTW, if there are any more self-pubbers ACX bound, I asked Kobo about putting my audio book up there, and this is what I got (i.e. might be worth not signing up exclusive with ACX right now, but wait for Kobo to be up and running):
"Hi ,
Thanks for your interest in Kobo Audiobooks! The KWL Development team is working hard to create a way for you to upload your audiobooks directly to Kobo via Kobo Writing Life and we are currently collecting a list of authors and publishers with titles ready to upload. We’re thrilled to hear you’re interested.
With your permission, we will add your name to the list of beta users for direct uploading and reach out to you in the coming months when we are ready to begin. Could you also please let me know how many titles you plan to have produced by December 2018?
Best,
Laura"
So, Koz, something for you to look forward to --in a few months you won’t just get the I-was-rejected-by-ACX wails, you’ll be getting the I-was-rejected-by Kobo wails too!