Blank screen if kids yell too much

http://superuser.com/questions/545329/blank-screen-if-kids-yell-too-much

My kids (4 and 5) yell a lot when playing games on our Linux box. I found an effective cure for this: I've told them that the computer doesn't like loud noises. So when they get loud, I ssh into the box and run:

chvt 3;  sleep 15;  chvt 7

This turns off the screen for 15 seconds. They get quiet, but not to the level that I would be happy with. So I need to continue this educational process, but I'm getting tired of doing this manually.