Not enough items 1. 6. 4 download. The easiest way to get Audible books on your Windows PC, MacBook or iMac is to use the Audible app, but the Audible books you download through the Audible app would be stored on your computer as.aa or.aax files, which could be opened by certain applications only. You may wonder whether you can download Audible audiobooks in MP3 format.Audible For Mac OsDownload..