I recentlly made some recordings in Murray Sunset National Park, in north w=
est Victoria, Australia. It was, I thought, a very quiet place in the morni=
ngs before the wind started, apart from the birds.
But in one recording, there is a thumping noise at random intervals, right =
through the two hour recording, which starts just before sunrise. Could I p=
lease have some opinions on what these noises might be?
At first I thought they were a car door being slammed - we were camped abou=
t 300m away, just over the hill - but there are far too many of them. Gunsh=
ots? Not allowed in the park, and the nearest farms are over 10km away, alt=
hough it's still possible, as there are feral goats in the park.
I'd also like to know if there's a good way of finding all of these in the =
recording without having to listen to it. I can only hear them if I use hea=
dphones, and if there's no background noise in the room, so it took me a wh=
ile to find as many as I have.
After I'd found a few just by listening, I used EQ to reduce everything abo=
ve 400Hz and increase everything below 200Hz. This makes them way more obvi=
ous to the ear, and I can spot most on the waveform, but it's not very plea=
sant to listen to. It also makes the sound of wingbeats sound similar, so I=
made a few mistakes.
Could there be an automated way of finding them all, or making them reliabl=
y more obvious on the waveform? I use Audacity.
Peter Shute
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