Mosquito ringtones

Have you heard about the "Mosquito ringtone?" Kids in schools everywhere are using this high-frequency ringtone that only kids can hear, in order to get calls in class without teachers hearing the ringer.
There's a site that lets you test how high a tone you are capable of hearing. Based on the results, it can assess your age and hearing level.
Here's my results:

You are in your twenties

You can still hear reasonably well and you can play this without my old fart colleagues hearing it which makes you feel kinda good. The highest pitched ultrasonic mosquito ringtone that I can hear is 15.8kHz

Find out which ringtones you can hear!

...actually, I can hear one notch higher if I listen through PC speakers and not headphones. Weird. But this description seemed accurate enough. Try it out!