Now that NPR blabbed about it, everyone knows about the mosquito ringtone, not just kids. Only the young can hear high frequency sounds. Some bozo invents a device to scatter loitering kids. Kids use high frequency ringtone to hide text messages from teachers.
Me? I make a 17KHz tone WAV file. (WAV files don't use the same lossey compression MP3 files do.) Beware that most cell phones probably can't reproduce a 17KHz tone anyway.
Enjoy!
