After a lot of testing and searching for a solution to play a sound
at login, I found a solution, however it needs some polish. When I login I managed to start audacious play an ogg file, but before that there are some other system
-like sounds played.
My command I put in /etc/xdg/lxsession/LXDE/autostart
In preferences I disabled the login sound
(preferences - login screen - play deselect login sound
Where are the system
sounds coming from ? Could be from the gnome session manager ?