OpenAL is a sound library. Copter Commander uses it to provide stereo sound effects. It is better than "esd", the default sound effect system, which isn't even stereo, and slows the game.
OpenAL does not have versioned releases. Further, the OpenAL API has not frozen yet, there is a chance that today's OpenAL won't be compatible with the Copter Commander version you're trying to build. For this reason you'll find an OpenAL snapshot with each copter-commander release. This snapshot has been rigorously tested by our dedicated crew of software quality assurance personell (read: it works for me :-).
The good news is: its easy!
Here's how I did it:
The long instructions are in
su - root tar -zxf openal-2-11-2002.tar.gz cd openal-2-11-2002/linux sh ./autogen.sh ./configure --enable-prefix=/usr/local make make install