Well, Rob and the Cornell website have certainly expanded my knowledge of
how minidisc sound compression works.

Since the sound compression in minidiscs is optimized for human ears,
obviously it's possible that the decompressed sound is suboptimal for ears
that hear differently than ours.

Possible.

However, until there's evidence that it *does* make a difference to birds,
I'll stick with my original thesis, that minidiscs will work for
"recreational" playback just as well as CD or tape. Bird hearing is very
similar to human hearing. And most birds don't seem that picky. As I
noted before, I've called in owls with imitations that were horribly
distorted renditions, at best, of the real sound (and yes, I've made
sonograms of my own renditions to compare with the originals). There's no
way in the world minidiscs could be as bad as the human voice/whistle in
reproducing bird songs. Each boombox or speaker I've tried has been
pretty good at adding its own (often plainly audible) style of distortion,
to no apparent ill effect. Whether there are leaves on the trees or not,
whether you're in open habitat or shrubs - all these things alter sound in
huge, easily demonstrated ways, but birds still respond to playback.

If I were conducting behavioral experiments on birds using recorded
playback, I'd stick with tape or CD, if I planned to publish the results.
Cornell's caution in this area is admirable, since they're a recognized
leader in recording and archiving bird sounds, and making original
recordings for scientific purposes, accuracy should come before
convenience.

But Cornell, a few years ago, was teaching people only ever to record on
one side of a cassette tape - oops! - another rule I've broken.

I guess it depends on your goal.

CH

Christopher E. Hill
Department of Biology
Coastal Carolina University Ph: 843.349.2567
P.O. Box 261954 Fax:843.349.2201
Conway, SC 29528 E: chill at coastal.edu

The indoor life is the next best thing to premature burial - Edward Abbey