SUBJECTIVE CUPULOMETRY: Threshold, Adaptation, and Sensation Intensity of the Vestibular Organ for Rotations in the Horizontal Plane

AT FIRST glance the vestibular organ seems much simpler than the cochlea. Mechanically, the membranous ampulla, with the cupula gliding inside it, constitutes a simple system with only one degree of freedom. The shape of the deformation of this system is independent of the frequency of the stimulus. There are no traveling waves, as there are in the cochlea, that change their pattern with the frequency of the stimulating sound. The movements of the cupula have been thoroughly described by Steinhausen,¹and the mechanical aspects of the system, consisting of the vestibular channel and the cupula, of the human labyrinth have been measured and described in a splendid series of papers by van Egmond, Groen, and Jongkees.* These papers form the basis for the development of cupulometry for clinical and research purposes. Their results have been confirmed and extended by Hallpike and Hood † in several studies carried out with