Most humans are born with the ability to hear frequencies from about 20 Hz (low) up to 20,000 Hz (high) but that range shrinks as we get older. A guy in England figured that meant kids can hear things adults can’t - specifically, very high frequencies. He created a device that pulses an annoying tone at about 15,000 Hz with the idea that when the device is used, it will repel kids while being unnoticed by adult.

Another use for this isn’t as unfriendly to children. Some cellphone ring tones  have a frequency that only children can hear and this allows them to use cell phone in class while older teachers remain oblivious to what is going on.

So what frequencies can you listen to?

Click here to find out

I, personally, can hear all of them :O, A word of warning. Don’t turn your speakers up too loud because this may be very uncomfortable. I found out the hard way

via

Popularity: 1% [?]