[wordup] Mosquito Alarm

[Adam Shand]

Awesome ...

Adam.

From: http://www.metro.co.uk/weird/article.html? 
in_article_id=14031&in_page_id=2

Pupils perform 'alarming' feat
Wednesday, May 24, 2006
A high-pitched alarm which cannot be heard by adults has been  
hijacked by schoolchildren to create ringtones so they can get away  
with using phones in class.

Techno-savvy pupils have adapted the Mosquito alarm, used to drive  
teenage gangs away from shopping centres.

The alarm, which has been praised by police, is highly effective  
because its ultra-high sound can be heard only by youths but not by  
most people over 20.

Schoolchildren have recorded the sound, which they named Teen Buzz,  
and spread it from phone to phone via text messages and Bluetooth  
technology.

Now they can receive calls and texts during lessons without teachers  
having the faintest idea what is going on.

A secondary school teacher in Cardiff said: 'All the kids were  
laughing about something, but I didn't know what. They know phones  
must be turned off during school. They could all hear somebody's  
phone ringing but I couldn't hear a thing.

'One of the other children told me all about it later. I couldn't be  
too cross, because it shows resourcefulness.'

The Mosquito technology is said to play on a medical phenomenon  
called presbycusis, or age-related hearing loss.

It is thought to begin at 20 and first affect the highest frequencies  
– 18 to 20kHz.

The device was developed by Merthyr Tydfil-based Compound Security.

Boss Howard Stapleton said: 'I think it is a giggle. A teacher would  
be able to hear the sound only from 1m away. Teenagers could hear it  
from much further away.'

But why don't pupils just set their phones to vibrate?