Removing Junk Mail Received Sound?

It's very annoying when I'm doing something and hear the "You've Got Mail" ding that Mail gives you, and when I check it's nothing important, only advertisements in my junk folder for Viagra, and the like! Is there any way to remove the sound from the junk folder which coincidentally is the same sound used for the inbox? It's really annoying but I do not want to uncheck the box for using sounds for other actions.