Sonic teenager deterrent Options

[pablo]

Interesting device ! A new gadget repels gangs of teenagers by emitting a high-pitched noise that can be heard only by under 20s.

Police are backing the Sonic Teenager Deterrent, nicknamed the Mosquito because of its sound, reports the Daily Telegraph.

It annoys teenagers so intensely they have to clutch their ears. Eventually they can stand it no longer and have to move on.

But because the body's natural ability to detect some frequency wave bands diminishes almost entirely after 20, adults are completely immune.
Source (http://www.ananova.com/news/story/sm_1726378.html?menu=)
Source2 (http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/02/16/noise16.xml&sSheet=/portal/2006/02/16/ixportal.html)

[Lina]

people.do.that.at.my.school.

being under 20, it drives me INSANE, they come in at registration (thats the morning). did you mean that the police use them, or the teenagers? cos the teenagers definitely do... :maad:

wheres the edit button gone?
ok so, the teenagers at my school dont use the same ones obviously (costing £622 and all) but they have whistles which the teachers cant hear.
personally i think its really mean for teenagers who dont cause trouble and can still hear the noise.