Currently in the field where I deployed two Audiomoths, that were tied on a tree (next to each other). Each recorder was tested with different batteries to test how long they last (Duracell and Eveready). I am currently using a San Disk Extreme - UHS 3 as recommended and the latest firmware - 1.3.0.
After 3 days of recording, when I retrieved the memory cards, I see a ton of white lines at high frequencies in almost all of the recordings. Why is this happening? What's the solution?
Thanks Alex. Upon a closer inspection, this appears to be natural sounds only (I stretched the spectrogram horizontally and you can see repetitive patterns each second). Shall keep you posted in case I encounter an issue like the one described above.
Is it possible to post the actual .WAV files somewhere (or email me an excerpt - alex.rogers@cs.ox.ac.uk). Which features are you concerned about? The high frequency vertical bands from 14 kHz to 24kHz? These looks like a natural sound to me - some sort of insect.
Here are two screenshots from different times of the day:
As far as I can recall, maybe of these devices was close to a wifi router when I was testing it before deployment. However, these recordings are coming from a dense rainforest fragment and I shouldn't be seeing those lines (well atleast not during the day, when insects are not vocalizing).
Can you post an example recording somewhere so we can see what problem you are referring to. Did you experience this testing the devices on the bench before deployment?
Follow up: Could this be because of recorders being placed next to one another? (As weird as that might sound, since someone had an issue with interference)