Hi and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
Open Audible app and you will see a gear like icon on the screen. Tap it and tap Settings. In Settings, first tap Refresh Library. This will redownload your books if there is any data missing.
Then tap Download Settings. You can change Download Quality to Standard or High there.
Please let me know if that didn't work, so I will continue to help you
Just checking. How is it going ?
If the above is not working, then do a reset. Press and hold down the Power button and Home button at the same time until it shows the Apple logo. When you see the Apple logo, release the buttons and let it boot. This will reset it. Then check Audible.
Note : Power button is the button you use to turn off your iPad or its screen. Home button is the round button at front bottom.