Well, it seems that teens have found a way to communicate with one another with out disturbing the older folks, sort of. There is a new ringtone going around named Teen Buzz or Mosquitotone. This tone produces a sound that, supposedly,can only be heard by people 20 and under.  This sound was originally developed for business owners by a company called Compound Security Systems Ltd to help keep this very same crowd from hanging out around their shops.  Now teens seem to be using this sound to their benefit to talk and text message one another in class.

I found a Mosquitotone on line to sample at freemosquitoringtone.com

I am 30 years of age and could hear it just fine.  Actually it hurt my ears a little.  Test it out for yourself, and let us know if you can hear it or not.  Oh yeah don't forget to leave your age.