Young at ear
How cool: I can hear a ringtone that you're not supposed to be able to if you're over the age of 20!
Like most people I'm sure, I've got a couple of ringtone profiles on my phone. My usual profile has the classic phone ring that everyone who has a 6680 seems to be use at a low volume. It's not too jarring for most places. I also have an outdoor setting that has a ridiculously loud crazy frog remix that I bluetoothed off of Beau Ambur a while ago. That beast can drown out any traffic noise I've encountered! The one thing profile I haven't been happy with yet has been my silent one. It's been just that: Silent + vibration. But the vibration still makes a heck of a racket and, depending on where the phone is at the time, I've been known to make yet more noise while jumping up in fright. Enter the Teen Buzz ringtone (which you can download it from here or listen to it online here).
The Teen Buzz ringtone has a cool story: Some kids decided to reappropriate a tone that was initially designed to ward them off and use it to their advantage. What started out as the Mosquito teenager repellent, eminating a 17Khz tone that only teenagers are supposed to be able to hear, is now a ringtone that kids can use in class without alerting their teachers to the fact. (Personally, I have grave issues with any society that thinks its OK to use a sonic repellent on their youth but that's another story.)
According to the web site of the firm that makes the Mosquito device, Compound Security Systems, the science behind it is thus:
There is a very real medical phenomenon known as presbycusis or age related hearing loss which, according to The Merck Manual of Diagnosis and Therapy, "begins after the age of 20 but is usually significant only in persons over 65". It first affects the highest frequencies (18 to 20 kHz) notably in those who have turned 20 years of age". It is possible to generate a high frequency sound that is audible only to teenagers.The cool thing is, I can apparently hear this thing and so I've put it on my silent profile. Now the test is to go somewhere public and see if "adults" (funny creatures who take themselves far too seriously?) can hear it! :)