FIG. 9.
(Color online) Level differences between DPOAEs measured using two different probe systems (ER10C and ER10X). Black lines show level differences expressed in SPL (black); red lines show level differences in EPL. The thick lines are smoothed versions of the thin lines. The measurements were made using FPL-calibrated stimuli and are shown only for f2 < 8 kHz to avoid contamination by system distortion in the ER10C probe (Richmond et al., 2011). The probes were inserted to similar depths in the ear canal as judged by the values of fλ/2 (7.7 kHz for the ER10C, 8.1 kHz for the ER10X).