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From: Pat Missin
Date: Mon, 9 Sep 1996 18:16:56 +0100
Subject: Futher thoughts on spectrograms

Having had some feedback on my experiments (see my recent posts on wood vs
plastic combs) and time to gather my own thoughts, some speculation on spectra:

1. The difference between wood and plastic was more noticeable (though still
minimal) on blow notes.

This could be a function of the shape of the reed chamber - the
"blow" pressure goes into the chamber before it reaches the opening of the
reed; the "draw" pressure goes throught the reed opening before being shaped
by the chamber. Therefore altering the sharp/size (and, maybe, the
material?!) of the chamber could affect the blow notes more. Any thoughts?

2. The difference between wood and plastic was more noticeable (though still
minimal) on notes sounded by myself, rather than by the machine.

When I said that people hear what they expect to hear, I did not say
this to get at people who disagreed with my conclusions, as I am sure I will
be as liable to this effect as anyone else. Also, I suspect that one's
technique could be directly linked (in a cybernetic feedback system - whoa!
are we on science-l?) to what you hear (or feel you should hear?). Perhaps,
when I play the chrom, I expect to hear a certain tone and (subconsciously)
my technique adapts to get the actual tone closer to the tone in my mind's
ear - hence the diffence is more noticeable when articficially blown,
without the interaction of a brain. This could explain the fact that a lot
of people claim to hear a bigger difference than the one my experiment
showed. Perhaps (I repeat, *perhaps*) when someone who firmly believes that
wood sounds "better" than plastic, plays a wooden-combed harp, they
automatically produce a better sound than they one they produce on a plastic
harp. Again, any thoughts?

3. Overall lack of noticable difference.

It occurred to me that I only took spectrograms of single notes. Due
to interactions of harmonics, perhaps chords would reveal a greater
difference. More work needed, obviously.

I should also point out that I believe the human auditory system to be far
superior in many ways to electro-mechanical systems. The only problem is,
that it is impossible to connect your ears and hearing centres to any form
of objective measuring apparatus. I sya if your ears tell you something,
then you shouldn't discount it by any means - but remember how subjective it
all is. Your mileage may definitely vary.

Work on overblows in progress...stay tuned!


Pat Missin - pa~lobalnet.co.uk

"...my music's a lot better than it sounds!" (with apologies to Mark Twain)
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