a Windows PC or Macintosh to download the files. Additionally, titles can be played on the PC (using iTunes or AudibleManager). Titles cannot be burned to CD with AudibleManager. According to Audible's website, they can be burned to CD using Apple's iTunes and some versions of Nero. (The DRM generally allows a title to be burned to CD once, although the resulting CDs can be played in any CD player and have no copy prevention.) Currently there is no support for Linux, although AudibleManager is known to work through Wine (though this is not officially supported by Audible)., Wine, WineHQ - AudibleManager, Dec 17 2014 Prospective buyers of media players can check the audible.com "Device Center" to verify whether the device will play .aa files, as well as play them at the desired level of audio fidelity. Audible players are available on Apple iPhones, iPods, Android, and Windows Phone devices. The Audible App allows for the downloading and playing of audio books purchased via Audible.com and allows the user to store multiple titles for play on mobile devices using the AA file format developed by Audible. Quality The following qualities have been available from Audible. Currently, only the "Format 4" and "Enhanced" formats are available for download. AAX files are encrypted M4B's. The audio is encoded in variable quality AAC format. While the vast majority of books are encoded at 64 kbit/s, 22.050 kHz, stereo, some are as low as 32k, mono. Radio plays are often encoded at 128kbit/s and 44.1 kHz. Additionally, many audiobooks in Germany are encoded at the latter bitrate and are marketed as "AAX+"; however, there is no difference in the actual file format. Digital rights management Audible's .aa file format encapsulates sound encoded in either MP3 or the ACELP speech codec, but includes unauthorized-playback prevention by means of an Audible username and password, which can be used on up to four computers and three smartphones at a time. Licenses are available for schools and libraries. Audible's content can only be played on selected mobile devices. Its software does enable users to burn a limited number of CDs for unrestricted playback, resulting in CDs that can be copied or converted to unrestricted digital audio formats. Because of the CD issue, Audible's use of digital rights management on its .aa format has earned it criticism. While multiple software products are capable of removing the Audible DRM ''protection