Repellent Ringtone

WashingtonPost.com: When it came out in Britain in December, the Mosquito sound system was supposed to be the sonic equivalent of a “no loitering” sign. Its annoying, high-pitched sound — which many adults can’t hear but most young people can — would act as a teen repellent.
Now, teens are staging a worldwide rebellion: Downloading the sound, or another ring tone in that same high-frequency range, allows them to hear their cellphones ring when their parents and teachers (mostly) cannot.
And the company that brought the Mosquito to market — Compound Security Systems Ltd. of Britain — is being barraged by a new market of companies wanting to sell a line of subversive ring tones.
“When we brought out the teenager repellent to market, we really didn’t think anybody would be interested in ring tones” in the same frequency, said Simon Morris, marketing and commercial director for Compound Security, who has been fielding hundreds of calls from companies and journalists around the world since the annoying ring tone became popular.
Teens Find a Ring Tone in a High-Pitched Repellent [WashingtonPost.com]