Sounds
From AssaultWiki
OpenAL
There are known problems for some people with using OpenAL. These people should try OpenAL-Soft (see below).
OpenAL-Soft
OpenAL may seem buggy for some users, especially those on unix based platforms. You can download OpenAL-Soft here. However, you will need to compile it from source.
SDL mixer
Early versions of AssaultCube (versions 0.93 and previous) use SDL mixer.