The city of Philadelphia is going to some interesting measures to keep trouble makers out of their city parks at night.

They are using anti-loitering devices called “mosquitoes” that emit high pitched tones so annoying that no one would want to be near it!

Here’s the kicker: they use specific frequencies so high that only teenagers can hear it! As you get older, you have a harder time hearing extremely high or low frequencies. Teenagers, on the other hand, CAN hear those very high frequencies (maybe they need more River rock and roll in their life?), and some are using it as a weapon!

Here…check this out…and if the players don’t appear, just refresh this page.

This is a speaker check…you should hear a very annoying tone:


This is 17 KHz, the tone Philly is using to keep kids out of their parks. If you are older than 24, you probably won’t hear this.


This is 16 KHz, if you are older than 30 you probably won’t hear this either.


This is 15 Khz, if you are older than 39 you probably can’t hear this one either!


This is 12 Khz, if you are older than 49, you probably can’t hear this.


This is 1000 Hz, if you are younger than 60, get your ears checked!


Share this with your friends…it’s really fun to see how your hearing stacks up!