For instance,
that passive headset blocked out the stall horn about 90% of the time. In
those brief moments when I did hear it, it was more of a fleeting impression
of something buzzing. I had thought a couple of times about suggesting some
sort of gizmo to RST Engineering to electronize the mechanical thingie for
me -- especially after a passenger asked me what the noise was and I
responded with, "What noise?"

Stall horns are for people who by the numbers. Yout typical single
engine aircraft does not need one. Use your ass.