Teen Repellent: High Pitch Whine Drives Away Teens

news.com.com — British shop-owner invents a device which emits a high-frequency pulsing sound that, he said, can be heard by most people younger than 20 and almost no one older than 30. The sound is designed to so irritate young loiterers that after several minutes, they cannot stand it and go away. Nov 29, 2005 View in Crawl 4