Thanks to 1WAY FM Trainer, Alan Mitchell for this tip:
Whilst Facebook has been designed to facilitate the uploading and sharing of picture and video files (which can both be taken right from your mobile device and interfaced via the mobile Facebook application), it does not allow you to do this directly with audio files.
Whilst you can upload and share documents such as Word and PDF files, an attempt to upload the popular mp3 or m4a compressed audio file formats of will simply lead to an error message that says “you cannot upload that kind of file”. This appears to be a deliberate omission on the part of the designers of “facebook”, in an attempt to discourage the sharing of audio files and likely copyright violations.
However, Facebook will allow you to upload uncompressed audio (WAV) files. Since these are around eight times the size of compressed audio files, the sheer size of these files is an issue.
A more elegant solution is to upload Ogg Vorbis compressed audio files. Ogg Vorbis offers comparable compression to mp3, and is the native compressed file format of the “Audacity” editing software we are using. Facebook will allow these files to be uploaded. To play back Ogg files, you could always open them up in Audacity, but a neater solution is to download a free Ogg file player on your computer, such as the “VLC Media Player”. Facebook will initiate a download which your computer will play straight away.