Does this really work because they're teenagers, or because they just haven't lost the upper levels of their hearing? I remember reading that we can (originally) hear up to 30,000 Hz, but as we get exposed to loud noises, we gradually get more and more deaf as our ears lose more and more of their capability. Something like the first concert you go to cuts out the upper 2000 Hz of your hearing. Which brings up an interesting point - will this work on teens exposed to so much loud noises (music, lots of concerts, construction, trains, etc.) that it just won't work on them?

By the way, a great role model for fathers everywhere:

"Okay honey, how much does this hurt?"

BZZZZT!!!!

"Ah, turn it off, turn it off!!"

"In a second honey. Daddy has to hurt you to show how much he loves you. Now, how about this?"

BZZZZT!!!

"AHHHHHH!"

Now I'm either going to revert to my old ways of playing Tetris for hours on end (convinced I can get a higer lines next time) or I'll have that theme song plague my dreams. Either will lead to hallucinations while looking at tiled floors.