As I was watching this video, I remembered of a very funny story of how me and my friends installed an app that allows you to release a constant sound with a especific frequency, and we tested in many ocasions. One of these ocasions was our physics class, where we generated a 17000 Hz sound (very annoying and agonizing sound) and the cool thing is that our teacher was not only old but on top of that, confiscated our cellphones and put them on his table, and for a period of 45 minutes, the entire classroom suffered with that sound, everyone except my physics teacher, that believed the students were being too distracted and finding excuses to leave the class. I could barely hold my laughter.,(reply>), Funny but this can actually cause hearing damage..,(reply>), @LootDeliveryMan yes some of us can actually hear higher pitched than your phone speaker can go(most likely, depends on the phone), I can hear about 20500 Hz and it's super annoying sometimes, I seem to be one of the only people who can hear it.,(reply>), @ccc310 i see you everywhere i go,(reply>), @Pedro L. Mammini oops,(reply>), @Worm on Crack *you're