Voltage in the fluid between the input- and ground-current electrode as a function of longitudinal distance from the input-current electrode, for an apical turn experiment. Each point represents the average voltage of the frequencies tested (i.e., 60, 120, 450, 810, and 1200 Hz) using a 1-mA current stimulus. The vertical lines above and below each point are the average value ± 1 SD. The line is the resulting exponential fit using Eq. 17.