> This recording was made about 4km inland at Wilsons Promontory in Victori=
a, Australia. There was a strong swell and there's a lot of surf noise in t=
he background as I expected, but I didn't expect to see it concentrated bet=
ween 2700 and 4000Hz on the spectrogram. Is that usual? Why so high?
Peter,
You have a recording with about 6Db signal to noise ratio with the bird jus=
t
breaking through the noise. If it was just surf, I would have expected it t=
o
be as loud to the ears.
I used a steep HPF to see what was left and this was a noise peak about 1KH=
z
and the broad peak around 3.5KHz. Possibly the mic was picking up more
background than you were expecting, but this would have shown up on the
meter if not in the headphones.
I also got a tinkling sound which is the sort of artifacts you get from hig=
h
rates of compression but this was a WAV file. Was there close water nearby?=
Was the high LF level producing intermodulation distortion somewhere along=
the recording chain?
My guess is that it was a high gain recording to get the bird and this
boosted a much less directional pickup of the background on the mic rig.
If you get a similar situation, first do a test recording of the background=
while slowly turning 360 degrees. Listening back, you will hear what
rejection the mic rig is giving you.
David Brinicombe
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