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Re: Introduction...

Subject: Re: Introduction...
From: "Tim" pteropus_tim
Date: Tue Jun 21, 2011 6:19 pm ((PDT))
Hi Peter,

Sorry for delayed reply, but I=E2=80=99ve been out doing fieldwork.

It=E2=80=99d be easy enough to place a mic or recorder up in the roost area=
, but you wouldn=E2=80=99t necessarily get anything useful from it. I=E2=80=
=99m going to try and post some pictures video and sound files to try and e=
xplain why. Flying-foxes are fascinating but frustrating animals to study, =
for a number of reasons=E2=80=A6

A mic or recorder wouldn=E2=80=99t bother them, they=E2=80=99d treat it wit=
h some initial suspicion, then their reaction would be interesting. For ins=
tance people have tried hanging CD=E2=80=99s in trees to deter flying-foxes=
 from roosting there (the bats almost fought each other to play with the CD=
=E2=80=99s); and have hung bright coloured safety vests, also to deter the =
bats (they hung on them). Whenever a film crew is filming our education bat=
s and they get to close, the bats either lean into the lens and lick it (gi=
ving patented Smudge-O-Vision=E2=84=A2); or reach out with their thumb and =
grab hold of the mic windshield. Or both.



From:  =
.com] On Behalf Of Peter Shute
Sent: Thursday, 16 June 2011 5:40 AM
Subject: Re: [Nature Recordists] Re: Introduction...

I don't know much about this stuff, but is it an option to place a micropho=
ne, or several, somewhere in the roost at night with the reasonable hope th=
at one of the subjects will roost close to it?

Surely getting very close would isolate the sounds better than any other op=
tions. Would they be disturbed by a microphone's presence or by cables or r=
emote controlled aiming?

Peter Shute

Sent using BlackBerry

From:  <naturerecordists%40yahoogrou=>
To:  <naturerecordists%40yahoogroups=
Sent: Thu Jun 16 02:41:58 2011
Subject: [Nature Recordists] Re: Introduction...

> b) allows me to get an averaged
> sound level and frequency distribution spectrum for the 10 minute duratio=
> of the recording (using Raven 1.4); and

Hi Tim,

I would perhaps recommend to use single (calibrated) omni-directional micro=
phone for this kind of analysis. As David already pointed out, summing up t=
he two stereo channels of an ORTF array could lead to odd effects.

> The shotgun mics I have access too (Sennheiser ME66 and ME67) do not seem=
> be able to abstract to this extent. Maybe a better mic (SennheiserMKH8070=
> may achieve this but sadly at the moment it's out of my league.#

No, for your particular application, the more expensive MKH series shotgun =
microphones will not provide any advantage because the pick-up patterns of =
all these models are quite similar. Actually, the MHK series microphones ex=
hibit a higher noise level at frequencies above about 10 kHz, which could b=
e a problem for your spectrographic analysis.

> I must admit to being a little worried about the frequent comments I come=

> across in various areas of the scientific literature regarding supposed
> "colouration" of the sound by the parabola? Although both reviewing posti=
> on this list, and doing a little research of my own into the published
> literature, this does not seem to be a huge problem providing you are
> concerned with on-axis recordings of above the critical frequency for the=

> dish diameter you are using. Or have I missed the point entirely somewher=

Yes, you are right. There will be some coloration caused by the parabola, b=
ut as you explained, there are no alternatives under these specific circums=
tances. Even a recording made with a shotgun microphone can be affected by =
coloration effects as soon as there are reflections off the ground or nearb=
y vegetation.

> If I understand things correctly, there's no necessarily perfectly correc=
> answer for anything in this game; like in many fields, the answer is usua=
> "it depends."



"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.

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