Take this, for example. The New York Times reports that
kids are using a high-pitched ringtone for their cellphones
on the assumption that, since hearing deteriorates with age, it will be inaudible to adults. The ringtone, which registers at a frequency of 17KHz, was developed, ironically, from a device that was designed to
rowdy teenagers in front of shops by broadcasting a sound that would annoy them whilst leaving older customers unaffected, but some clever person turned the idea on its head.
Of course, while the tone is supposed to be inaudible to people over roughly the age of 30, it’s not a hard and fast rule as several kids found out to their dismay. My 26 year old ears had no problem with the tone, which sounds to me like a TV that’s on mute. I wonder if perhaps the difference is not merely age but also
. The generation that’s hitting thirty now could be more able to discern these types of sound, since they’ve grown up with more familiarity with electronics which might generate sounds of this kind. But that’s a theory I just came up with right now, so who knows?
If you want to hear the sound for yourself, you can find a recording