ultrasonicsThe news about teens being able to hear certain frequencies well below what adults can hear is nothing new.  I did think it was was rather clever, using those tones as ring and text tones to avoid detection by adults.  Ever wondered where your cut off point is?  I did and stumbled across this site. You can play several ranges of ultrasonic tones at the following site and even download them for your own use:

http://www.ultrasonic-ringtones.com/

I don’t think I did very well.  At 15.8kHz my sensitivity cut out.  After that, I can only percieve the slightest whine and even then only without distractions.  After 19.9kHz I got nothing at all.  To be certain you are testing yourself correctly, you should here a sharp, crisp whine, NOT a hum or static (that’s generally an audio relic of the mp3 quality).   Good luck, bat-people.