Change Startup/Log in Sound In Karmic Koala

How to change startup / log in sound : Karmic Koala 
What you need: your favourite sound file in .ogg format.
Step 1:

• Go to System -> Preferences -> Starup Applications

• Look for “GNOME Login Sound” in the list. If you don’t want to hear anything at startup, uncheck this box.

If you want to change the sound, click Edit button. You should see this:

/usr/bin/canberra-gtk-play -–id=”desktop-login” -–description=”GNOME Login”

• Change “desktop-login” to the name of the sound file you want, without file extension. 

example: /usr/bin/canberra-gtk-play -–id=”new-login-sound” -–description=”GNOME Login”

• Click Save and close the startup dialog.

Step 2:

• Now you have to copy the new sound (.ogg file) to /usr/share/sounds/ubuntu/stereo/

• You need root permission to copy the file into this directory which can be done by running nautilus as root.

gksudo nautilus /usr/share/sounds/ubuntu/stereo/

• Finally, browse to the folder and paste the file there.

Step 3:

• Log out and login and enjoy your the new startup sound.

You can convert .mp3 or .wav to .ogg sound file using Sound Converter. Can be installed using software center or Terminal command :

sudo apt-get install soundconverter