They misrepresented it a bit. According to what i have read, they seek out elevated places, dig a small hole to give themself better arcustics and emmit a sound, that can reasonably be described as the openning notes of "dark side of the moon".

Those large, bassy wavelengths are excellent at reaching increadibly long distances, so females in a large area will know, that a male exists. You may know this phenomenon from listening from music. You may also be aware, that it is almost like you "feel" those sounds as permeating your bodie rather than comming from any real direction. The poor kakapo female will know, that a male exists, but will have no idea about where to look for it!