The "mosquito" ring tone is what they call it. It's really fun to play with those high frequencies because as you get older, your ability to hear those super high frequencies deteriorates. Unless, of course you're a dog. Me and my friends were playing with a frequency generator last week, seeing where our cut offs were. And true enough, the older ones in the group couldn't hear the higher frequencies (around 19,000 hz).try it for yourself... http://forums.xisto.com/no_longer_exists/ This makes for a good ringtone, but just be careful you don't have a young teacher. I heard a story of a young teacher hearing it instantly much to the amazement of her class who were used to old farts with bad hearing...