Mean click-evoked ABR thresholds for right ears of Beethoven mice. (A) ABR thresholds for isogenic Tmc1+/+ (C3H-+/+), Tmc1Bth/+ (C3H-Bth/+), and Tmc1Bth/Bth (C3H-Bth/Bth) mice. (B) ABR thresholds for (C/B)F1-Tmc1Bth/+ (C/B-Bth/+), (C/D)F1-Tmc1Bth/+ (C/D-Bth/+), (C/B)F1-Tmc1+/+ (C/B-+/+), and (C/D)F1-Tmc1+/+ (C/D-+/+) hybrid mice. ABR thresholds for isogenic C3H-Tmc1+/+ and C3H-Tmc1Bth/+ mice are shown as in A. When responses were undetectable with a 95 dB SPL stimulus, the threshold was calculated and presented as 95 dB SPL. Vertical bars indicate standard deviations.