• Assigning a sound to an event

Let's say that the list of sounds included the one where Basil Fawlty alias John Cleese says "It's in the bin" and that you would like to hear it whenever you make the trash can go fat by putting something in it. You would:
1) click on Fill Trash
2) select the "It's in the bin" sound from the list
and optionally
3) select the volume at which you want this particular sound to be played.

Repeat steps 1) to 3) for each event that you wish to have a sound played for, clicking on the little arrows to switch to more events as needed.
To disengage a sound from an event, select the event's radio button and click on the "No sound" line at the top of the sounds list.

If you wish to hear a sound from the list before assigning it, select it by typing its name or using the up/down arrow keys, then press the right arrow key. Pressing Enter will assign the sound to the currently selected event, just as if you clicked on it.