It varies according to whether the plane is climbing, cruising or descending. From flying gliders, I'd guess about 50/50 during cruise. The sounds occupy differ

It varies according to whether the plane is climbing, cruising or descending. From flying gliders, I'd guess about 50/50 during cruise. The sounds occupy different parts of the spectrum - wind noise is pretty white, but more in the higher part of the spectrum. Engine noise is a very deep, black-ish noise. You can hear the difference between a jet in climb and approach - the former makes a much louder, deeper noise. The latter sounds just like a skydiver, incidentally - if you stay at a quiet drop zone, you'll often wonder if there's a jet somewhere high up in the sky.