are there....

[flip city]

any apps in the depository that can convert audio formats ?

[nightflier]

There are many guides for doing it on the command line.

I tried this simple script, it works for me. Maybe something to play with until soundconverter becomes available.
http://www.webupd8.org/2010/03/zenity-ffmpeg-bash-script-to-convert.html

[Locator]

I was looking for a MIDI player, and strechedthin was nice enough to tell me that I could download a multimedis bonus disk (in ISO format) from the following link:

http://www.opensourcebistro.com/blog1/

just look for the flashing download link on the right, and when you get Brasero working correctly then use it to create the bonus CD, after which you re-insert it and double-click  "Launch.sh", and enter the root password (if necessary), then go to the "Audio" section, and you will find some files that will let you do what you are trying to do.

[MarkGrieveson]

There's one called soundconverter (1.5.4-i586-1vl70)