Comment 88 for bug 116990

I noticed this problem in Gutsy, as well. One day (sorry I can't be more specific) I started hearing a burst of static at the login screen. Didn't put it all together until I was trying to figure something out in Hardy and triggered the exact same sound (playback of the startup .ogg sound from within administration -> login window -> accessibility).

In addition, killing all of pulseaudio does not fix the problem.