Linux Whenever a user login to Ubuntu, a login sound plays. The login screen is your gateway to the GNOME Desktop: it is where you enter your username and password and select options such as the language you want GNOME to use for your session. If you don’t like it then you can easily disable it. To disable it follow these steps:
First go to System >> Preferences >> Startup Applications.
Now uncheck the GNOME Login Sound. And click on Close.
If you want change this sound then first confirm that GNOME login Sound is checked in Startup Application, then Follow the steps :
Open Run Application by Alt+F2.
Now copy paste “gksu nautilus /usr/share/sounds/ubuntu/stereo” and click Run.
Now remove or rename a file desktop-login.ogg.
Paste here your favorite sound file, that must be .ogg format, and save this file with desktop-login.ogg name.