http://theoatmeal.com/quizzes/soundThe Teenage Audio TestClicking the play button below will produce a tone that is generally only heard by people under the age of 25. It has been used as a deterrent device to keep teenagers from loitering in malls and shops, and sounds similar to a buzzing mosquito. The elderly and people with hearing damage often cannot hear the sound.
Go to site to take test.
http://theoatmeal.com/quizzes/sound
I took the test, it was kind of like a dog whistle sound - very high pitched and it bothered me listening to it.