Start with your posted sound clip and see if you can get the same results I did. Post where you get stuck.
If you succeed, you may want to try submitting a test to ACX.
ACX starts with The Robot who automatically tests about the same things Audacity ACX Check does. Are you overloading, how loud is it, and where’s the noise.
https://forum.audacityteam.org/t/measure-between-23db-and-18db-rms/32770/16
This is a thing on how dB works.
https://forum.audacityteam.org/t/audiobook-mastering-version-4/45908/68
Then your Audition goes on to Human Quality Control where an actual human evaluates and tests your submission for presentation, emphasis, reading style, oral defects, and theater. You can look at this as someone coming in off the street and paying real money to hear you read in a pleasant room. This isn’t the “good enough” podcast stuff.
Also down at this level, they start to worry about things like who wrote the book you’ll be reading and can you produce documents that give you rights and permissions.
– This isn’t a tidy web page yet. –
ACX Audition
Also Known as ACX Test Clip and ACX Sample.
An Audition is a short reading you can submit to ACX to prove your performance quality before you submit longer works. ACX will review your work and post comments. The work does not have to be produced using Adobe Audition.
Works must be perfect and ‘Retail-Ready’. ACX will not change any work once you submit.
Auditions should be around three to five minutes long.
Auditions should be mono (one blue wave). Stereo is accepted, but your production must be consistent.
Auditions should have 0.5 to 1 second of Room Tone at the beginning and 1 to 5 seconds of Room Tone at the end.
Auditions must be in MP3 sound format with constant bitrate of 192, minimum.
Auditions must have sound peaks no louder than -3dB.
Auditions must have a voice RMS (loudness) value between -18dB and -23dB.
Auditions must have Room Tone (natural background room sound without you performing-or moving-or breathing) quieter than -60dB.
You can submit this audition to ACX after filling out a questionnaire.
https://audible-acx.custhelp.com/app/browse/c/3549\
Audacity has tools to help you meet the technical requirements.
Audacity Forum has a section for Audiobooks. You have to register to post. New Posters may have a delay before posts become visible.
https://forum.audacityteam.org/viewforum.php?f=64\
Audiobook Mastering.
https://wiki.audacityteam.org/wiki/Audiobook_Mastering\
Audiobook Testing - ACX Check.
https://wiki.audacityteam.org/wiki/Nyquist_Analyze_Plug-ins#ACX_Check