Where do I find system sounds?

After installing gm-notify I see the option of hearing a sound every time a new e-mail arrives in my Gmail inbox, but I don't know where Ubuntu (10.4) stores the system sounds to assign one. Any ideas? Thanks.

/usr/share/sounds/gnome/default/alerts

would be a good place to find sounds for this purpose.

/usr/share/sounds/ubuntu

is a sound theme. Sound themes can be chosen in sound preferences. 'ubuntu' is the only sound theme installed by default. I would advise against editing files in this folder directly. A better thing to do, if you wanted to edit the sounds in this folder, would be to copy it (perhaps to /usr/share/sounds/ubuntu-modified) and change the index.theme file to have a different name.

sudo cp -R /usr/share/sounds/ubuntu /usr/share/sounds/ubuntu-modified
sudo -H gedit /usr/share/sounds/ubuntu-modified/index.theme

Once this is done, you can safely edit the sounds in /usr/share/sounds/ubuntu-modified.

/usr/share/sounds

If you remove/rename a sound, it should stop. Or you can replace it with an .ogg sound (.wav works too... I think...)

You can find the bulk of the system sounds here: /usr/share/sounds/ with the majority of them being in /usr/share/sounds/ubuntu/stereo

You can also try

Sound > Sound Effects

I have mine switched off since I find sound effects annoying

For some sillier sounds (which I sometimes like to use for system events), you can also check here: /usr/share/gnome-games/sounds

You can download more system sounds for Gnome at Gnome-look.org, too.