A “Silent” Ring Tone
June 13th, 2006
I’ve heard various reports about this, from the initial creation of a device that disperses crowds of young people, to the actual use of ring tones in class with teachers who couldn’t hear it, but this article has a sound file to download. When I played it on my computer, I could hear a very slight hum and that was it. The creator had to ask his kids (or grandkids) whether or not the sound was bad enough to chase people away. The New York Times says you have to be over 40 or so in order not to hear it, but other articles give the cutoff age as 20.
http://www.nytimes.com/…
(via Digg)
UPDATE: One person wondered just how degraded his hearing was, and he generated some test tones to find out. They are available for download here. My hearing is fine through 13,000 Hz then drops off sharply to the point where I can just barely hear 15,000 Hz.
