Scifi, You have a point with the noise cancelling headsets. I mostly don't hear my SkyDemon warnings from my (leg supported) cradle, and I have a normal set of good ol' DCs, not even noise cancelling ones!
We fly from a relative short and grass RWY with trees in front and we have to be careful with our approach speeds, we aim for 60KTS on short final and we make close to a full stall landing flare, which normally causes the horn to start moaning just before touching.