Figure 15.

Sound pressure at the umbo required to produce a constant level of cochlear input across frequency. Shown are P_U,th that produces a constant stapes velocity of 10 nm∕s (equivalent to a constant stapes volume velocity of 6×10⁻¹⁵ m³∕s) (black line) and P_U,th that provides a constant cochlear sound power input Π_C of 1.5×10⁻¹⁸ W (solid gray line, only at frequencies where Re{Z_C} is positive). Also shown is P_U,th for Π_C=1.5×10⁻¹⁸ W computed by assuming that Z_C is purely resistive (dashed gray line). The mean gerbil audiogram (Ryan, 1976) is shown by the dotted line and squares. (a) Logarithmic frequency scale; (b) linear frequency scale.