While not music related, per se, I found this incredibly interesting. The BBC reported on a theater that is using an “ultra sonic tone” to keep people under 25 from lingering outside. From their article:

“Crime Reduction Officer Bob Walton elaborated further: ‘Effectively, it’s a transmitter which sends out a specialised frequency noise which according to the manufacture is particularly audible to young people under the age of 25.

“He said: ‘I’m in my fifties and when it’s turned on all I can hear is a very faint buzz. But I understand from young people who have been exposed to the noise, it is very annoying.’”

You can listen to an mp3 of soundwave here. I’m 19 and it gave me a headache after about 30 seconds of it. I’d be interested to know if you all could hear anything, and if so, what age you are. Apparently if you can’t hear it, you just a sort of buzzing sound.

Strangely enough, now kids are using this to make “teacher-proof ringtones.” What smart kids.