(A, C, E, G) Means and standard errors of the displacement ratio of the reticular lamina (RL) to basilar membrane (BM) at 50, 60, 70, and 80 dB SPL. (B, D, F, H) Phase differences between the RL and BM vibration. Latency (Δτ) was calculated from the phase slope and presented next to phase difference curves. (I) The magnitude ratio decreases with sound level near the best frequency. (J) Phase difference as a function of frequency shows no significant change with sound level. Data in panels (A–H) are presented as mean ± SEM.