This story made the rounds a few weeks ago. It's about a specific, annoying soundwave that most adult can't hear, and most teenagers can. Shopkeepers in London had been using the sound to keep teens out of their stores, then teens started using the sound as a ringtone to use in class that teachers couldn't hear. According to this other story the cut-off for hearing it is age 25.
Some people feel the ringtone aspect is impossible or a hoax due to cellphone speaker limitations. It's all interesting, but I'm more curious about the mp3s of this sound these articles link to and what you guys hear when you listen to them. (I strongly suggest you lower your volume first and ease into them.)
Let's call this one from the BBC story: #1.
(All it sounds like is ambient street noise to me. Not annoying at all.)
and this one from the NPR story: #2.
(On laptop speakers, I hear some kind of faint whistle when I really crank it up, but nothing so annoying that it would keep me out of a store. On decent speakers it's unbearable.)
Give them a listen, then post your experience with each one along with your age.
The comment board is NOW CLOSED.
Updated - Ochen wrote:
Well, I heard nothing unusual in the first one, but did hear the “mosquito” in the second. Being the ever-skeptic, and as I believe that my 31-year-old hearing is pretty good, I thought you guys were full of it and that there wasn’t anything to hear in the first one.
I brought the mp3 into my handy-dandy spectral analyzer, and wouldn’t you know it, there was something there, hanging between 15000 Hz and 17000 Hz. I dropped the pitch about 5 percent and could hear it very clearly.
I then did an experiment to find out where my limit was. It’s right around 15000 Hz, but add ambient noise and it gets lost.
I posted a set of mp3s at http://www.ochenk.com/tones that go from 10000 Hz up to 18000 Hz. Every file is of the same volume, pure tone.
Find your limit.
Ochen K.
I can barely hear up to 16,000 hz on my decent computer speakers, definitely less on the laptop, but I still don't hear anything in #1. (Damn teenagers and their "hearing".)
Based on this older story about the tone, it sounds like mp3 #1 might be more accurate since people say it pulsates.