Mild impairment of hearing threshold but similar OHC function in BDNF^Pax2 KO mice. A, Average ABR thresholds (horizontal dashes) and single ear thresholds (circles and squares) for control (black dash and open circles) and BDNF^Pax2 KO mice (red dash and squares). Average ABR thresholds ± SD for click stimuli were 11.2 dB higher in ears from BDNF^Pax2 KO mice (32 dB SPL ± 9.27 SD, n = 26/52 mice/ears) than in ears from control mice (20.8 dB SPL ± 6.04 SD, n = 27/54 mice/ears, t test: p < 0.001). B, Average frequency-specific ABR thresholds ± SD confirmed a significant increase in thresholds in BDNF^Pax2 KO mice over most frequencies measured (controls: n = 27/27 mice/ear; BDNF^Pax2 KO: n = 26/26 mice/ear; two-way ANOVA: p < 0.001). C, D, DPOAE growth function ± 95% confidence interval at f2 = 11.3 kHz (C) and 2f1–f2 DPOAE thresholds ± SD (dB SPL f1) (D) in control (n = 7/12 mice/ears) and BDNF^Pax2 KO mice (n = 7/12 mice/ears), revealed mostly similar OHC thresholds and signal amplitudes in both mouse lines.