Especially when you working with other people in an office, the system's beep can be very annoying to others. E.g. this can occur when you hit the ESC key twice.
A very simple solution (which I got from here) is to add a line in your ~/.inputrc file (or create the file with the following line, when you haven't got one):
Please login again to activate the settings. That's all!
In other forums, the option
is also recommended, but if you switch to a X-server free console (e.g. by hitting), the beep occurs in that case, too.
also does the trick. There are some more things xset can solve in a quick way, e.g. screen saver, LED on/off, mouse acceleration...