The latest fad in the cell phone industry is the mosquito ring tone. It came about after a crafty British man invented a device called The Mosquito. It is a device that emits a very high frequency tone meant to annoy teenagers (adults are unable to hear the tone). Businesses would blast the frequency outside their store to keep loitering teens away from their storefronts. Some crafty students decided to convert the same technology into a ring tone that only they (teenagers) could hear! By utilizing this free ring tone, they could now receive phone calls and text messages while in class or school without teachers knowing it.
Click here to test out your hearing. Even thought I am 25 I can only hear 39 and younger (15khz) frequency.
WARNING: I now have a headache from listening to them too much; especially the super high frequency ones.
Erica's Blog 