Fig. 8.

(a) Umbo hysteresis Hu as a function of pressure change rate, measured in six animals. Hysteresis increases constantly as pressure change rate decreases. (b) Normalized umbo hysteresis, measured in six animals: Umbo hysteresis Hu is multiplied by the ratio of stapes peak-to-peak amplitude over umbo peak-to-peak amplitude PPs/PPu at each pressure change rate to make values independent of changing amplitude and to compare umbo to stapes at the same value of displacement. Also, normalized hysteresis increases constantly as pressure change rate decreases.