Thanks Alan! Is there a physics reason as to why we are unable to locate the origin of these frequencies? I suspect it has something to do with the long wavelengths, the relatively close spacing of our ears and the ability of the ear/hearing centers to do the necessary triangulation calculations based on the rough data it is likely receiving.
I do believe that extreme low frequency sounds are difficult or impossible for us to localize. The thing I question is the often quoted cutoff frequency for this. I suspect it is lower than 80Hz but I am fairly certain that it is not lower than 50Hz. Either way, I think we have all learned some interesting new things today.
