omichalis
Date: Sat Jul 31, 2010 12:48 pm ((PDT))
I had to upload the whole recording instead of this excerpt for clarity - =
but I have not time to convert to mp3 and do so -
it' s only this strange sound i- it is also accompanied by some other tiny =
sounds next to it - like those you can hear to the other recording.
The exact placement was :
the hydrophones buried just a few cms under the sand with a small stone eac=
h on top to hold them still. All this inside the water a depth of 30-40 cm=
under it. Their distance with each other was about 1 meter. I then heard t=
his strange thing for the first time and I repositioned the left one severa=
l time close to the other as I tried to get a stereo recording.
I never managed to get a decent stereo recording, but I only got this oscil=
lating sound only in the first recording, I can still here strange sounds a=
s if sth is digging the sand in all the recordings from the right microphon=
e only.
I' m not sure if some kind of electromechanical problem could cause this. I=
' m not experienced in that kind of problems.. But I exclude the possibilit=
y of the stone directly hitting the mic. I had to pump up the gain enough t=
o record this sound, a stone hitting on the mic would result in severe clip=
ping for sure - this actually happened in several cases in the parts that I=
cropped when editing the recording.
m
On 31 =CE=99=CE=BF=CF=85=CE=BB 2010, at 9:15 =CE=BC.=CE=BC., James Shatto w=
rote:
> It seems too metric to be a natural / critter type source. Although wave=
action with the sand blasting the rock holding it down might account for i=
t. I guess we'd need to know how deep, how far apart, did you bury the cab=
le too? Sound does travel up and down the cables. Maybe not at that ampli=
tude. The metric seems to be approximately 2 seconds and 6 seconds (+/- 0.=
5 seconds). With that interval and variance pretty much all of the ones I =
took a timestamp of line up. Which could just be the turn around time of t=
he outgoing and incoming waves.
>
> As far as radar, there are many types of radar. And some of the military=
stuff you can't get down at the marina.
>
> - James
>
> --- On Sat, 7/31/10, Dan Dugan <> wrote:
>
> From: Dan Dugan <>
> Subject: Re: [Nature Recordists] what is this creature/sound ?
> To:
> Date: Saturday, July 31, 2010, 12:10 PM
>
>
>
> > It sounds like a problem in one of your hydrophones.
>
> I agree; if it was a mic in air, I'd say for sure it was an electronic os=
cillation, often called "motorboating," from the lack of acoustic around th=
e sound. But I'm not used to listening to hydrophones, so my intuition migh=
t be all wrong.
>
> -Dan
>
>
>
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