Figure 3.

Measured and model SFOAE phase-gradient delays N_SFOAE versus frequency. Delays are expressed in periods of the stimulus frequency. The symbols × and ◻ show delays measured in the tokay gecko at probe levels of 20 dB SPL (ten ears) and 30 dB SPL (three ears), respectively (Bergevin et al., 2008). Data points whose corresponding SFOAE magnitudes fell within 10 dB of the noise floor are not shown. The gray dots show model N_SFOAE values obtained from numerical simulations of 25 different ears (i.e., irregularity patterns). The solid curve is a loess trend line (Cleveland, 1993) fit to the pooled model results. The dashed line gives the analytic approximation 6Q_{10 dB}∕π [Eq. 14], where Q_{10 dB}(CF) is a power-law fit to ANF data (Manley et al., 1999).