http://www.palmpreforum.org/sounds/high-pitched-ringtone/?topicseen
Here's a tone (ringtone) that supposedly only young people can hear.
Very high pitched - if you can hear it...
It is simply a 17KHz frequency. Most people over the age of 30 can't hear it at all.
Pretty neat cause I asked my dad and mom to listen to it and they were like "im waiting, im waiting, I dont hear anything!!!" hahaha