I am sure it is not new scientific discovery that 1) human ears cannot hear all sounds 2) some can hear more than others 3) aging affects hearing. But it is not until recently that people started to use such scientific facts in everyday life.
Someone in UK has deviced up some ringtones (follow the link to find a sample sound file) using a high frequence so that only people younger than a given age (say 17) can hear it. Sure, it is a statistical threshold, in the sense that, some teens may not hear it whereas some 30-years-olds can still hear it.
The scientific reasoning is that human ears become less sensitive over the years. Thus the range of freqeuncies a person can hear becomes narrower as he/she ages. When I told Xiaoli Meng from Harvard about this during the ICSA meeting, he was wondering whether there is a frequency that the elder can hear while the youngsters can't. I am afraid that this is not a fair game.
I am sure blogs around the world have covered the same topic but I still feel I should blog it.
Of course I tried to hear the sound but I can't hear it. It gives me strange feeling. I am not upset because I am old in some definition now. Rather, I am upset because that there is something I had the chance to hear but I didn't and now it is too late for me to hear it. I am sure there are tons of things like this that I have missed. Still, having something so materialized thrown right into my face like this makes me feel bad.
Besides the sentimentals, I also thought of the implications of this. I wonder whether babies cry sometimes because they are annoyed by some high-pitch sounds that the parents cannot hear. If this is true, I wonder whether we should have a meter at home that detects sounds of all frequencies and their magnitudes. Just a thought.