> I made a recording at a wetlands that has nearby industry=97not great for=
nature recording, but good for a binaural demo. There=92s a gravel pit beh=
ind, which has large trucks. There=92s a small airport a few miles away, so=
a bit of private plane activity. There=92s also a water treatment plant on=
the other side of the pond, so ignore the steady background noise, it=92s =
not the fault of the mics. The head was placed such that there were a lot o=
f birds to the right and left, but not many in front, unfortunately.
Charles,
I had an in depth listen to your recording last night and made notes. I
heard high jets, low jets, single engine and twin engine aircraft and what =
I
took to be helicopters. I also got a conversation RHS which could be
transcribed after suitable filtering. :-)
First off, I wouldn't expect much difference between front ant back as the=
dummy heard is bald, I have long hair, so my ears wouldn't differentiate
between front and back. On my headphones, everything was in front, but the=
rear sounds sounded a bit more hazy in location.
I didn't detect a ground echo by ear or analysis, but in a reed bed (?), I=
wouldn't expect much reflection. I got no height information from the
planes. Try some dummy "hair" like cloth or a mass of loose string or a foa=
m
pad on top and to the back of the head to see if that gives some front-back=
or vertical resolution as in an aircraft or bird flying overhead.
I tried to restore the HF which dropped sharply above a few K but
unsuccessfully as there was little past the peak at about 5K. This was
non-directional - just missing. There are two strong dips at about 1K and
Message: 1.
Subject: 7K which I can't explain but which colour the recording. These would
correspond to cancelling reflections about 170mm and 100mm away, but these=
would have to be strong reflections.
< I=92m getting a sense of vertical direction, but maybe it=92s my mind
playing tricks on me.
Stereo recording and especially dummy head recording is a bag of tricks. Th=
e
art is to get the tricks working for most people. :-)
< Most of the activity otherwise=97trucks, people talking, etc=97is behind.=
I detected that not by my ears but by a lack of definition in the front
image. As I said, my ears ar "trained for long hair".
David Brinicombe
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