(A) ABR and (B) DPOAEs were measured in 6-week-old male WT (blue curve) and Hyp (red curve) mice from mixed litters. (C) Threshold shifts between WT and Hyp mice were similar in ABRs and DPOAEs, except for the mid-frequency region spanning 16.0 – 22.65 kHz where DPOAE shifts (solid line) were about twice as large as ABR shifts (dashed line). (D) DPOAE I/O-functions at 8, 16 and 32 kHz. (E, F) SP/AP ratios at 8, 16 and 32 kHz are increased in Hyp mice (red curve/column) compared to WT mice (blue curve/column). *p<0.05, **p< 0.01, ***p<0.001, ****p<0.0001 (2-way ANOVA with Sidak’s test for multiple comparisons and two-tailed unpaired t-test).