I manged to get the voice to work.
I downloaded firestormviewer from http://www.firestormviewer.org/.
I copied the files libvivoxoal.so.1, libvivoxplatform.so, and libvivoxsdk.so from the lib directory of firestormviewer to the lib directory of Second life.
That did the trick.
To get sounds to work I just run "cp /usr/lib/i386-linux-gnu/libopenal.* ./" that seems to be enough to get things working.