(Gah... stupid keyboard shortcuts... just accidentally deleted my entire post with one quick typo...)
: So, it depends on your definition of "normal". Hearing these things
: should be possible for any properly developed, undamaged human ear. But
: that's not really "normal" these days...
I'd heard that the extremes get hit first, both upper and lower limits. Maybe the lower frequences get damaged more, or we notice it more because there are more octaves in those frequencies. (Octaves go by doubling the frequency. The lower octaves don't have as many frequencies in them as a result, so I'm guessing they're more vulnerable to total loss.)
And today's environment IS noisy. Busses and trucks are big culprits, and I suspect that all those iPods and Walkmans aren't helping much. Heck, I have to be careful with my mp3 player when riding on the bus; I've found the volume maxed a couple of times without even thinking. Gotta get better noise cancelling, though that'd leave me dangerously unaware when walking.
-- Steve's managed to retain a fairly wide sensitivity range despite working in an auto factory for two years, attending air shows for 20 years, listening to rock for 25 years, and practicing at an indoor pistol/rifle range for four years. How'd that happen?
