Original downloaded audible file
Audfree is an one-stop streaming audio solution to convert DRM-ed audios, including Apple Music songs, iTunes & Audible audiobooks, as well as non-DRM audio files to MP3, WAV, FLAC, AAC for playing on any device.
Download URL for Win: https://www.audfree.com/download/AudioConverter.exe
This program allows you free to try before buy. The only difference between trial version and full version is limited conversion time.
Click Add File icon at the lower left corner, then you can selected your downloaded audible aa, aax files to audfree main interface. You can also drag and drop the files to the main interface directly.
Audfree Audible AA, AAX to MP3 converter supports not only MP3 format, but also other common used audio formats like M4A, AAC, FLAC, WAV, M4B. You are also allowed to set the codec, channel, sample rate and bit rate for the output files.
Click convert button to start converting DRMed audible audiobooks to unprotected MP3 format quickly. After conversion finished, all your audible AA, aax files will be changed as MP3 format losslessly.