Figure 4.

Amplitude and phase in the high-frequency region plotted against frequency normalized to the resonance frequency. (A) Amplitude (A1) and phase (A2) of $p$ calculated from nonexpanded form (Eq. 13). The unit of amplitude is $\overline{f}$, and ${\alpha }_c=1$ is used. (B) Amplitude (B1) and phase (B2) of high-frequency expansion (Eq. 15). With membrane conductance $\sigma$ (dashed) and without membrane conductance (dotted). Three plots in each correspond to $\gamma$ values of 0 (blue), 1/2 (purple), and 1 (red), respectively. (C) Difference between nonexpanded equation and expanded equation with $\sigma$. Relative difference of amplitude (C1) and difference in phase (C2). No difference for $\gamma =0$.