Originally Posted by Checkmite
What I didn't say clearly enough is that the best way right now is simply to listen to the 2 soundfiles that you and S. linked to, back-to-back.
Because we don't have enough samples of the noise, and nothing clear, no amount of slowing down is going to reveal much new detail, or give an insight, I think.
Happy to keep trying.
If it really bugs you, I can dig up the slowed down AP sound again, or make it again. I might have cleaned up and thrown it out.
As for what I'm saying: I've made a living with my ears and technology and this sounds like a bad recording of crickets.
It's simply the "think horses, not zebras" school of diagnosis.
Last time I checked I could only hear to 13k. But I'm in a quiet room with great gear.