High schoolers have figured out how to receive text message alerts on their cell phones without the teacher being the wiser. A new ring tone is too high-pitched for adults to hear it.
Called the ‘Mosquito’, a Welsh security company had developed the tone for store owners to disperse young people loitering in front of their shops while leaving adults unaffected.
Many adults develop what's referred to as 'aging ear' and can't hear higher-frequency sounds. As a test, the ring tone was played for a classroom of first-graders — and all of them could hear it, while the adults didn't hear a thing.