Firstly, if this is the wrong place for this, I'd be happy to know the correct place for this and I'll move it there.
I have two PCs which share an audio interface. My laptop is connected via USB and uses it as its sound card. My Desktop (runs Linux so will be called Linux PC from here on) inputs into inputs 3 and 4 of the interface which is routed out the monitoring outputs. If it's relevant, I'm using a Focusrite Scarlett 6i6 (2nd Gen). I was watching something on YouTube on the Linux PC about an experiment involving sound, one of those things that let you try at home. Interested, I opened my DAW on my laptop, set it to read inputs 3 and 4 (the Linux PC), and opened a spectrum analyser to take a look at the frequencies of sound.
My spectrum analyser shows the audio has a pulsing every 10 seconds with the pulse lasting around 7 seconds, with two pulses in unison at ~20kHz reaching up to ~24kHz and the second at ~40kHz reaching up above the scale which tops off at ~43kHz. My sample rate is 88.2kHz.
What is this?
I've looked at this question and accepted answer, which is the only thing I could find that has come close to be even remotely similar to what I'm seeing and I don't quite know if it's related or not. The post mentions to filter out anything above 1/2 the sample rate to filter out aliasing artefacts, but 1/2 my sample rate is 44.1kHz which plants the lower pulse well below this area and the higher one just below it.
The screenshot was taken when (seemingly) no audio was playing. I can't tell if the plugin has some kind of automatic gain control that makes the maximum amplitude fit in the spectrum's colour gradient or not, but when audio plays it is significantly weaker on the spectrum but definitely still there.
I've also recorded, intensely amplified and lowered the pitch and it sounds like data, but again, what data?