My children are enthused by anti-adult ring tones. Adults can't hear as high as children. So an appropriately-pitched ring tone can sound in the classroom, say, without the teacher hearing it. (Presumably you have to speak in a high squeaky voice as well for this to be really useful).
The principle is sound, anyway. My hearing cuts out before 12KHz. But a loud 16Khz will send the children diving for cover with their hands over their ears, while I blissfully wonder what the problem is.
http://www.freemosquitoringtones.org/fr/
Which points to the other use of this phenomenon. The 'Mosquito' is a device used to disperse unwanted teenagers at shopping centres. As the inventor says, "It's very difficult to shoplift when you have your fingers in your ears."
http://www.nytimes.com/2005/11/29/international/europe/29repellent.html
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment