🚀 go-pugleaf

From article <sa0KhqO00Uh7M2R25C@andrew.cmu.edu>, by bas+@andrew.cmu.edu (Bruce Sherwood):
> The analogy with audio is that a CD with frequency response out to 10
> MHz would not sound better than one with frequency response out to 20
> KHz, because the human ear can't hear the higher frequencies.

  Well, it probably would sound a bit better. Consider this:

A 20KHz sample on CD looks something like this


 * * * * * * * * * *
* * * * * * * * * *

which is just a dumb square wave. Sure, it's at high enough of a pitch 
that most people wouldn't be able to discriminate between it and a pure sine 
of the same requency, but what happens if, say, you have a 20,001Hz waveform? 
Then, 20KHz just isn't enough to provide a nice, "symetric" waveform. Thus, 
you get a somewhat harsh sound. If I were really after a "human limits" sample, 
I'd bump the rate up to around 30KHz to minimize the distortion. (Assuming that 
a 40KHz sample is "wasteful".) 
  Since there are indeed people sensitive enough to these at-the-limits
conditions, we shouldn't write off any increase in the sapling freqeuncy as
wasteful just because simple math says "you can't hear anything higher than..."
The truth is, we CAN hear the effects BELOW the maximum frequency. Here's
an analogy (and an excuse to post here): The human eye can only discern between
a limited amount of colors, especially in small areas. The number is quite
small (on the order of 100s). So, should we abandon 24bit color displays since
we _shouldn't_ be able to tell the difference? Just because our hearing doesn't
necessarily scream at us "yuck" like our eyes do doesn't mean we should ignore
what does exist. I'll keep my 24bit color, thank you. And I'll also get the
SUPER-CD player that sample at a higher rate because _I_ can tell the diff.

Robert Minich
Oklahoma State University
minich@a.cs.okstate.edu

DISCLAIMER: One who takes forgotten floppies.