nyceddie@webtv.net (E. L.) wrote in message news:23522-3F57ACF3-
244@storefull-2377.public.lawson.webtv.net:

About the 'alien noise' (spacebug.wav)
Group: alt.alien.visitors
Date: Thu, Sep 4, 2003, 8:34pm (EDT+4) From:
random.dlyj@dbbv.invalid.com (Mr.�4X)

Sorry for the late reply. (I downloaded the spacebug.wav file but I had
to transfer it to another PC which has a soundcard via a floppy to check
it out, during which I also 'discovered' a faulty disk :( )

The high pitched noise sounds very much like if it would come from an
animal. I think it's very small - a bird, some kind of an insect, or
maybe a bat.

el: "Assumptions with nothing to back it up."

Larger animals could make lower pitched sounds.

The frequence and duration of the sound is similar to the sound of
CRICKETS, except #1. crickets make their noise in short bursts (perhaps
4-5 such noises in each burst) and #2. AFAIK they live in grass instead
of trees.

el: "So, not a cricket!"

At least not the type I know in Europe.
 

After actually listening the recording, I have doubts that the noise is
from bats. If it is then it's probably some kind of communication, not a
sound used for echolocation - it's simply too long to for a sound used
to get a precise echo from small objects (bats use echolocation to find
small insects).

el: "So, it's not bats."

I'm not completely sure.

There might be an easy explanation for the claim that whatever is making
the noise occurs more frequently now than in the past. If it is actually
an animal, then recent global warming or some other development may have
allowed its population to grow.

el: "Throw in some sun spots while you're at it and don't forge the
kitchen sink."

The barking dog was easy to recongize (and ignore), but the entire
recording has a very strong background noise. The background noise
sounds like an electric motor, most likely a fan (the cooling fan of a
laptop?) and it trashed nearly all audio bands, except for the highest
frequencies.

el: "The background noise is easy to identify.  Assuming that the
recording was made on a handheld recorder, since there was no
overwhelming sound the recorder's electronics simply maxed out looking
for sounds.

Unlikely. If that had happened then the background noise would be 
different. It was almost certainly isolated fan noise (could also be from a 
house-top fan). Traffic noise is different, so is electronic noise. And 
don't forget that the barking was not loud.

 If a loud sound had occurred, the background noise would
have been reduced until the loud sound stopped then it would have
resumed.

Assuming the background noise on the record would be low-intensity 
background noise overamplified by the recorder. In that case the barking 
would also reduce the BG noise level (IIRC it didn't).

 This has a technical name I cannot think of right now.
Sometimes the term "pumping" is associated with the technical term.  So,
the answer is still "I/we don't know what causes the sound."

Not certainly, but I have a suspicion about it.