Daft question but are you getting the beep from your speakers?
Not knowing your setup, the first thing that I would do is to check all the
connections. i.e. carefully unplug and then replug them. Its amazing how
these leads can be pulled out by house cleaning, pets, kids etc

Have a look on the bottom toolbar. You may have to click the < button
to show the hidden icons. Check these. You may find a volume control.
Left click on it for a slider control or right click for a more extensive control
panel. ( This will all depend of course on how your computer was set up.)
Another daft point. Have you any earphones plugged in?. These can cut off
the sound to the speakers. ( Now who would be daft enough to forget something
like that?

errr...... well I've only done it twice and today I forgot that
there is an on/off switch on my wireless ones. Daft present anyway.)
Keep us informed mate.
Tomkin