2006-10-14 09:14:36 · 4 answers · asked by Anonymous in Consumer Electronics ➔ Other - Electronics
Yuo must be looking for one of these??
http://news.bbc.co.uk/1/hi/wales/south_east/4415318.stm
2006-10-14 10:11:59 · answer #1 · answered by jayktee96 7 · 0⤊ 0⤋
You can make your own for free! Download "Audacity" (just use a search engine to find it, won't be hard to find). You can then generate a 18kHz sine wave and loop it over and over. Most adults cannot hear it because as people age, they aquire high-frequency deafness, yet it will really split right through the heads of younger people (late 20s downwards).
2006-10-14 11:21:41 · answer #2 · answered by Rich 5 · 0⤊ 0⤋
Yes, they do exist and to an extent, they work. It is possible to find and download this noise as an MP3, but I do not know where from, or.... it is possible to find a circut diagram and build one yourself. I believe the Maplin catalogue stock the parts and may sell a kit.
I know these work, as I can not hear it, but I know a local shop keeper uses one to deter children from loitering near her shop, the children do notice it and do not loiter.
2006-10-14 09:24:36 · answer #3 · answered by mittobridges@btinternet.com 4 · 0⤊ 0⤋
called a mosquito emits a buzzing noise only audible to people under twenty five.
2006-10-14 09:27:20 · answer #4 · answered by puzzled? 3 · 0⤊ 0⤋