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Re: Binaural test

Subject: Re: Binaural test
From: "J. Charles Holt"
Date: Wed Jul 15, 2015 8:55 am ((PDT))
David,

There=92s definitely a lot going on in the recording. The wetlands is a ser=
ies of former gravel pits that have been converted into ponds, and although=
 they=92re are surrounded by industry, they are one of the most vibrant and=
 active birding spots within 100 miles. Pelicans, blackbirds, orioles, warb=
lers, shore birds, hummingbirds, raptors=97not to mention turtles, snakes, =
lizards, skunks, beavers. I even identified a track in the mud that was eit=
her a bobcat or a small mountain lion (I=92ve got the pictures to prove it!=
). I=92m lucky to have it, although it=92s a frustrating place to record, a=
nd it=92s closed at dusk.

As I noted, I didn=92t do any EQ on it yet. Logic Pro doesn=92t have very g=
ranular controls for that, and I=92m not sure the best way to do it (not be=
ing an audio engineer). I=92ve created several comparison recordings with a=
nd without the pinna and ear canals, so I can at least see the differences =
between them. Once I find a way to try and compensate I=92ll post it again.

You=92re right about the lack of definition in the front. I=92m still confu=
sed by that=97I get very good accuracy on sounds recorded behind, but it so=
unds muddy in front. Could it be the shape of the head? Lack of hair? Only =
further experimentation will tell.

>From everything I=92ve read about binaural (which is quite a lot at this p=
oint), my best hope is to simply get recordings that have a good sense of s=
pace to them, and I think I=92m on my way in that regard. For a total budge=
t of around $130 including the mics, I think the results so far have been p=
retty good.

Thanks for your careful listening and attention. It=92s clear from your exp=
erience that you have a lot to teach, and I=92m eager to take in as much as=
 I can.

=96 Charles

> On Jul 14, 2015, at 7:59 AM,  [naturerecordists] <natu=
> wrote:
>
> > I made a recording at a wetlands that has nearby industry=97not great f=
or nature recording, but good for a binaural demo. There=92s a gravel pit b=
ehind, 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=92=
s not the fault of the mics. The head was placed such that there were a lot=
 of 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 wha=
t 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 th=
e
> 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 th=
e
> 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 f=
oam
> pad on top and to the back of the head to see if that gives some front-ba=
ck
> 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=

> 1.7K which I can't explain but which colour the recording. These would
> correspond to cancelling reflections about 170mm and 100mm away, but thes=
e
> 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. =
The
> art is to get the tricks working for most people. :-)
>
> < Most of the activity otherwise=97trucks, people talking, etc=97is behin=
d.
>
> 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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