In the Settings window, audio settings are here:
In the Windows version, you can choose SDL and PortAudio. SDL is the traditional backend audio interface, and works quite well. PortAudio is more modern and allows for many different backend audio systems, and offers more latency control:
The light grey area is where we select how the system is accessing the audio card(s) and the area below that is where we select the specific card we wish to use. This window is similar on OS X and Linux as well.
To test an audio driver, open ...