Check in Control Panel> Sounds and Audio Devices> Sounds> Events. Look
through the programs that have added themselves in here and their
associated sound files for their program events. The ricocheting program
should show up there....
Only time i remember hearing something like that is with
the yahoo messenger when you get an email. You can turn
it off though - you'll have to check in the settings cuz
i don't remember how to turn it off.