Clicking this menu brings up the following sub-menu:

The alarm selections are as follows:   

• Clicking "None" means you want no alarms to sound. 
• Clicking the entry just above the horizontal line allows you to select a WAV file for the alarms. You can select any WAV file from any directory. 
• The clock also offers PC-speaker sounds, which can be selected below the horizontal line. Note: the PC-speaker sounds do not work correctly on some PCs. This feature is only provided for backward compatibility -- it is no longer supported. If you have multimedia options installed, we recommend you use a WAV file for your clock sounds.