From: "Graham Evans"
> I'm not sure if the annoying nature of mono sound (especially through
> earphones) is solely due to this effect but I am prepared to be convinced=
.
This effect, which is basically our ability to select from available
stimuli, depends on having a stereo field. We can select because the
stimuli have a directional component in stereo. It's how we are built to
hear. In mono all sounds are effectively from the same direction and we
cannot select.
Our hearing evolved for stereo. That's why mono is annoying, it's not
natural enough. Primarily the advantage of stereo is expanding the
apparent sound from a point to a 2d (or even 3d) space, the way we hear
sound normally. Cocktail party effect is our mind responding to that.
> What sort of (stereo) post-processing would anyone suggest to treat two
> monophonic voice tracks (interviewer and interviewee), other than the
> obvious meaure of seperating the two sources by moving them slightly off=
> centre in different directions. I am using audacity. A hint of stereo
> reverb might help - but I am recording the voices outdoors so won't want=
> too much of this.
There are binaural filters for placing mono into a stereo field. They
can do a little better than just panning. But it's far better to start
with stereo.
One Idea I had for your problem where you seem to want to interview
while walking a path. How about mounting a good ambiance mic on
something like a steadycam for mics and have that out ahead of your
speakers on the path? That could record the interviews and ambiance in
one go. Though in any way you record the interviews while moving you are
going to have a problem of footsteps recording. I know the SASS I use
could handle getting the interviews in this situation (and the footsteps
would record, unfortunately).
The alternative is to record the ambiance in stereo, then record the
interviews in a quiet studio setting and lay them into the ambiance
using the binaural filter techniques and traditional mixing.
> Bernie and Kevin and anyone else who can help:
> With outdoor use of these mics what sort of wind protection do you
> recommend?
This will depend on the wind level. It's not just wind protection, but
you need enough suspension too. Using the lavs on someone you might look
at what Dan Dugan does with his shoulder mounted mics.
In general you need at least 2-3 layers of dead air space formed from
material that's acoustically transparent while slowing the wind. Many
materials can make their own noise from the wind and are to be avoided.
Artificial fur is generally a good outer layer for this reason, it tends
to not add noise. For something the size of lavs you will need something
to keep the fur away from the mics. Rycote softies use a open foam. I
believe Dan is using molded "plastic canvas" which is available in craft
stores. They have a sphere of that a few inches in diameter that should
do the trick.
For my M/S I'm using fur outer, a rycote or sennheiser zeppelin which
consists of a plastic supporting mesh with a fine screen or flannel like
material to stop wind. Inside directly on the mics I use knit baby
socks. That works fairly well. The entire structure is supported by a
suspension off a rail backbone. You can see some of the details here,
before I started using the baby socks:
http://frogrecordist.home.mindspring.com/docs/ms_setups.html
These are commercial windscreen/suspension setups which I obtained
piecemeal off ebay.
My SASS is internally suspended with the mics on silicon o-rings mostly
to keep down handling noise and uses a lycra and foam slip on cover.
Outside of that a artificial fur cover.
The Telinga parabolic I have a circular piece of soft thin fleece like
material that slips over the dish opening.
Realize that whatever you do, none of these methods remove any of the
wind noise in the environment. For instance here in the south even a
light breeze makes the pines hiss like a noisy mic. As wind increases
the sounds produced in the environment will limit the usefulness of any
wind protection.
Walt
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