libcanberra is an implementation of the XDG Sound Theme and Name 
Specifications, for generating event sounds on free desktops. 
It comes with several backends (ALSA, PulseAudio, OSS, GStreamer, null) 
and is designed to be portable.

This requires GConf and sound-theme-freedesktop, and you'll need to make 
sure GTK_MODULES contains "canberra-gtk-module" - the easiest way to do
that is to have something like this in your shell initialization:

  if [ -z "$GTK_MODULES" ] ; then
      GTK_MODULES="canberra-gtk-module"
  else
      GTK_MODULES="$GTK_MODULES:canberra-gtk-module"
  fi
  export GTK_MODULES