Happens to me every single time out at the old Garthdee farmhouse and I swear its not interference from my kit because I've tested it indoors with nothing.
The static always kicks in roughly 30-40 seconds before anything worthwhile shows up on the recorder, like some kind of audio preamble you didn't ask for. My theory, for what its worth, is that whatever causes the EVP phenomenon also causes some kind of electromagnetic disturbance first - basically it needs to "warm up" the local field before it can actually manipulate sound. Ley line intersection near that site probably doesn't help either, the energy there is already pretty active without any provocation.
Has anyone tried logging the exact duration between the static burst and the first clear EVP hit? I've been meaning to do it properly with timestamps but I always get distracted during the session itself. Would genuinely love to see if theres a consistent window across different locations because if there is that's actually useful data for predicting when to pay close attention.