I had a quick look and it seems that it's all actually handled by libhildon-plugins-notify-sv.so (nsv_plugin_play_event). But that library seems to be closed. Interesting strings in it: nsv_profile_get_volume nsv_profile_get_system_volume nsv_util_valid_rootfs_sound_file nsv_util_valid_sound_file register_alarm_clock register_alarm_calendar pb_playback_* (libplayback-1) It may also be a problem in the way it interacts with pulseaudio (pa_* -- libpulse, libpulse-mainloop-glib, libsndfile). If anybody (freemangordon?) has the chance/time/skills to decompile libhildon-plugins-notify-sv.so, we might get to the end of this..