The role of the pinna in human localization

The pinna, or external ear, has been shown experimentally to perform an acoustical transformation essential to localization in human hearing. The mathematical form of the transformation is given, the inverse to the transformation is shown to exist, and a theory of localization constructed from the evidence. The theory is extended to reverberation and other facets of human hearing. The basic theorem applied to the study is 'in order to know, the inverse to the transformation of perception must be constructed'.