Frequently Asked Question
1. Click the Ding next to the second radio button. Ding is the name of the default alarm sound.
2. Select Choose A Different Alarm Sound File
3. A file chooser will pop up. Select the audio file you want to play as the Alarm Sound, then click the Open button.
By default, it might be set to only show you .wav files. Change the selector on the lower-right, above the Open button, to "All Media Files" to see all types of sound the application can play. (There are also more narrow options in that filter, like .MP3, etc.)
4. Notice that the name of the Alarm Sound has change... in my case, to Darth Vader. Click Test Alarm Sound to test the sound you selected.