It is strange that Linux Mint has such great sound effects in Cinnamon and they can all be heard, but they do not work on the Linux Mint XFCE desktop. Fret not. The effects are there, but the sounds have to be enabled. This applies to the XFCE desktop in any Linux distribution.
To enable these in XFCE session, open a terminal windows and do the following
sudo apt-get install sox gnome-session-canberra <enter>
Enable the sounds in the xsettings
$ xfconf-query -c xsettings -p /Net/EnableEventSounds -s true <enter>
$ xfconf-query -c xsettings -p /Net/EnableInputFeedbackSounds -s true <enter>
Default sound theme selected is LinuxMint. It should be available in /usr/share/sounds.
vi ~/.profile <enter>
Add the following 2 lines at end of the file
Save the file.
To autostart the login sound, go to Settings Manager -> Session -> Startup -> Application Autostart with:
Name = Login Sound
Command = canberra-gtk-play -f /usr/share/sounds/LinuxMint/stereo/desktop-login.ogg
So far so good.
This is the main thread from which above was possible https://ubuntuforums.org/showthread.php?t=2263834