I'm sure some of you have already heard of this, but it was news to me. Today in class I was talking about hearing and hearing loss in the upper frequencies. And a couple of my students said, "Oh, like the mosquito ringtone." They were passing comments, and I didn't want to get into it, so I left it until I got back to my office to investigate.
In short, a theater in England was having problems with the large number of youth gathering in their square. Compound Security (http://www.compoundsecurity.co.uk/) supplied them with a high-pitched tone (18-20 kHz) to pipe into the square. It worked. The kids dispersed. And since it was too high for most adults to hear, it didn't bother their patrons. For the BBC radio program that discusses it, go here: http://www.bbc.co.uk/wiltshire/content/articles/2006/04/04/mosquito_soun d_wave_feature.shtml In the radio program, they have a recording from the square playing in the background, but according to my evening students, you can't hear the high-pitched tone. Apparently that MP3 cut off the higher frequencies. But at the bottom of the page, there's an MP3 of just the recording from the square where it can be heard -- if you're young enough. I'm not. All I hear is the hum of traffic and people in the background. But my younger evening students were plugging their ears, and my older students were left looking at each other. (I think this MP3 peaks at about 17 kHz if I was reading the classroom's audio software correctly.) The descriptions students gave were interesting -- like a cricket, like dying birds. In the news program they say that people over 25 can't hear it, but of course there's much variability. One of my nearly-30 students said he could hear it. And now the kicker. It's available as a ringtone (in the US: http://www.fork.com/, in the UK: http://www.mozzyworld.com/). Reportedly, students are now using it to hear the arrival of text messages in class because their older teachers can't hear it. -- Sue Frantz Highline Community College Psychology Des Moines, WA 206.878.3710 x3404 [EMAIL PROTECTED] http://flightline.highline.edu/sfrantz/ -- Office of Teaching Resources in Psychology Assistant Director, Project Syllabus http://www.lemoyne.edu/OTRP/projectsyllabus.html --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english
