gdm and bell

[famrom idecnet com (Guillermo S. Romero / Familia Romero)]

Does anybody know how to ring the computer bell from a script launched in
logout? The play command works, but I need old speaker in this case.

I know that I have to put scripts in PostSession dir so gdm runs it when
user logs out, but it seems that traditional "echo -en \a" does no work (I
suppose that X VT does not provide bell per se). I have to test via xterm,
but I would like a cleaner solution if possible.

If via xterm, how do I enable the audio bell without enabling root's audio
bells (in manual says that scripts run as root, so it will use root's X
settings, no?).

Thanks in advance.

GSR