Yeah this matches exactly what I've been noticing with my own recordings. I do a lot of sessions up on the fells near Caldbeck and probably 4 or 5 times now I've caught this really distinct burst of static - almost like interference - right before something comes through that sounds like a voice. It's not just random noise either, the pattern feels different to the usual background stuff. More like a surge.
What I keep wondering is whether its actually the entity drawing energy in some way, like pulling from the surrounding electromagnetic field before it can manifest enough to produce sound. I've read a bit about the stone tape theory and whether certain landscapes might amplify that.
Does anyone know if this has been documented properly anywhere? And has anyone tried logging the exact duration between the static burst and the EVP to see if theres a consistent gap? Feels like the kind of detail that could actually tell us something useful if enough people compared notes.