Because right now you don't seem to have one, and the OpenAL license is GPL2, which is a viral license. Just thought you should be aware of that.
To clarify, a viral license means that if you use the code, then your code has to have the same license. Which means legally anything you've done since you added OpenAL *should* be GPL2 and the code should be available.
I'm not saying you should do it, but I am saying you should probably have a license and seek a replacement for OpenAL if that's not your intention.