Neural Funneling along the Skin and between the Inner and Outer Hair Cells of the Cochlea

An attempt has been made to show that (1) the rotating tones in hearing, (2) the rotating vibrations on the skin, (3) the difference limen for the smallest perceptible distance on the skin, and (4) Mach's law of contrast are all a consequence of the same funneling action of the nervous system. In many situations the role of the funneling action can be better understood if a neural funneling unit is proposed, taking into account that a local stimulus produces both an area of activity and, around it, an area of decreased sensitivity. Since the inner and outer hair cells in the cochlea show a difference in sensitivity, the funneling action between these areas of different sensitivity has been investigated. It has been found that, between such areas, the locus of the sensation is continuously displaced as the intensity of the stimulus is increased. This suggests that along the organ of Corti there is a longitudinal displacement produced by variations in frequency, and a radial displacement between the outer and inner hair cells produced by variations in sound pressure. Thus there seems to be a pitch‐loudness coordinate system in the ear. The cochlear model (described earlier) with nerve supply was therefore further developed into a cochlear model with more and less sensitive nerve supplies, in order to represent the outer and inner hair cells in the organ of Corti.