I've read about this.
It's even on Wikipedia here
Apparently, teens have been able to upload this frequency onto their mobile phones as a ringtone.
That way their phone could ring in class and the teacher couldn't hear it.
Here's where to get it: http://www.jetcityorange.com/mosquito-ringtone/
There's a link there to hear it yourself...if you can!
I downloaded the MP3 and couldn't hear it.
But then I downloaded the WAV version and could definitely hear it.
You know when you hear a particularly loud noise and your ears ring?
It sounds like that.