For those wanting to get the game to use surround sound, here are some tips.
First, for your information, the game is made to filter whatever hardware devices it finds on your system, thus making them not appear in the game options and launcher device selectors. This was made this way due to several incompatibilities and glitches detected when testing them. You can always force the game to use an unsupported device by manually editing the settings file and setting the sound device to the desired ID (reference on available devices should appear in a game output log). Note that we cannot provide much help with any problems arising from trying these.
Second, for those wondering where their Generic Hardware devices are, OpenAL Generic Hardware devices will not work on Windows versions from Vista or newer, due to Microsoft dropping support for DirectSound3D. More details in the following link:
Now here is some trick that should work for everyone. There is a software implementation of OpenAL called OpenAL-soft that supports surround sound setups on pretty much any capable sound card. You can get it here: http://kcat.strangesoft.net/openal.html#download.
Just download the Win32 binary package and look for a 'soft_oal.dll' (should be located in the openal-soft-<version_number>-bin/Win32 directory in the package). This 'soft_oal.dll' file should be copied to the game redist folder, i.e. where the game exe is located. After having done so, in the launcher and game options there should be a new selectable sound device. Make sure to configure your speakers properly in control panel, and select this device in the game options. And voilà.