DomotiGa can play sounds, it uses the build in sdl sound component. simply place your wav files in the "~domotiga/sounds" directory, and enable the module in the Setup -> Module menu. If House Mode is muted, sounds are not played. (so you can sleep at night).
Look at the System Debug page to see how you can play your sounds from the code.
Startup log entries:
2008/11/11 22:39:17 Sound support enabled. 2008/11/11 22:39:17 1 soundfile found.