/////Those 'sferics' are random (ish?) radio interference recorded on a stereo receiver - of course they sound like stereo. If you recorded it on two stereo receivers and played it back from four corners it'd sound quadrophonic. That has nothing to do with the price of fish. I was talking about Uranus - that's a different kind of stereo altogether.////

sferics is caused by lightning and it's only picked up on AM receivers.