Walt wrote:
> All of this assumes you are in a nice acoustically perfect test
> facility. The effect of polar variation on the incoming sound is as
> nothing compared to the effect of the environment around the sound
> source. Record with mono and you have no clue about that, record in
> stereo and you have at least a little chance to analize the complex
> soundfield of natural situations.
>
> The biologists I work with have no trouble at all doing scientific
> analysis on calls recorded in stereo, nor do I. Sonograms, the primary
> tool for birds and frogs are just as useful if not more useful done
from
> stereo recordings. I think I'll stick with the opinions of the
> biologists, which is they strongly prefer stereo for their scientific
> work if they can get it.
>
> It's is not just a matter of more pleasant at all. It's a matter of
> gaining a lot more information. Which can, of course, make analysis
> more complex as there is more information to gain.
>
> Walt
>
Okay Walt, it is probably not adequate to generalize here too much.
Of course, it always depends on the specific purpose of your
recordings and the specific conditions in the field. There are many
situations where the attenuation at higher frequencies on sounds
arriving from off-axis directions simply does not matter.
Sure, there are other negative environmental factors in the field that
will also influence the quality of my recordings. However, I would
always try to minimize them and optimize my microphone set-up in order
to get the best possible results.
For instance, if I record single bush crickets at close distances in
the field that partly sing in the ultrasonic range
(http://www.avisoft.com/sounds.htm#insects), it is VERY important to
point the microphone exactly at the animals. Otherwise, the resulting
recordings (and also the slowed-down versions for listening) would be
quite poor.
It is my impression that many recordists are not always aware of that
microphone pointing issue because they believe that stereo is 'always'
better.
I could also imagine that it might be sometimes useful to be able to
get additional information on the direction of the incoming sounds
that can be provided by a stereo recording. But in my experience, most
researchers use a single directional microphone for their work because
they usually try to keep their equipment as simple as possible. In
case they are interested in the specific locations of the vocalizing
animals, they use a microphone array with more than two microphones.
Regards,
Raimund
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