Auditory phenotyping of clarinet mice at P28 (E) and P42 (F). ABR threshold measurements show that Clrn2clarinet/clarinet mice (red) exhibit a severe-to-profound hearing loss affecting all frequencies tested. At 16 kHz in Clrn2clarinet/clarinet mice, the mean ABR hearing thresholds vary from 55-65 dB SPL at P16, 60-90 dB SPL at P21, and to 80-100 dB SPL at P28 and P42. Age-matched Clrn2+/+ (black) and Clrn2clarinet/+ (grey) controls display thresholds within the expected range (15-45 dB SPL) at all frequencies and time-points tested. At P16, all eight Clrn2clarinet/clarinet mice exhibited recordable ABR responses for each frequency tested and the click stimulus. For the longitudinal ABR study, at P21 and P28 three of the seven Clrn2clarinet/clarinet mice were found to not respond at the highest intensity stimulus (90 dB SPL) for at least one frequency-specific/click stimulus. By P42, five of the Clrn2clarinet/clarinet mice were found to not respond at the highest intensity stimulus (90 dB SPL) for at least two frequency-specific/click stimuli. ABR data shown are mean ± s.d. ***p<0.001, one-way ANOVA. 