Fig. 8
Hearing function assessed by auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE) in bcan−/− mice. a ABR thresholds of bcan−/− mice (red) were elevated compared with wildtype mice (black) in response to both click stimuli (bcan+/+: 16.7 ± 3.3 dB SPL, n = 6/12 animals/ears; bcan−/−: 20.0 ± 3.6 dB SPL, n = 6/12 animals/ears, p < 0.01, t test) and pure tones, which covered the frequencies of best hearing of mice (at 11.3 kHz, bcan+/+: 33.3 ± 6.8 dB SPL, n = 6/12 animals/ears; bcan−/−: 38.8 ± 6.8 dB SPL, n = 6/12 animals/ears, p < 0.05, t test). b Sketch illustrating a click ABR waveform with waves I–IV indicated at the positive peaks, respectively, and the definition of latency as the time point of the negative (leading) peak of the individual wave. c Growth functions of the latencies of waves I to IV (mean ± S.D.) show consistently larger mean latencies for all four waves and all stimulus levels (except latency of wave I at 35 dB above threshold) in bcan−/− mice (red) compared to wildtype mice (black; n = 6/12, animals/ears each genotype). For clarity, the S.D. is plotted in one direction only (+ S.D. or − S.D.). d DPOAE maximum amplitudes averaged over 10–18 kHz did not differ between genotypes (bcan+/+, black: 23.3 ± 4.5 dB, n = 7/13 animals/ears; bcan−/−, red: 24.2 ± 2.1 dB, n = 6/12 animals/ears, p = 0.537, t test). * p < 0.05, ** p < 0.01. Data are presented as mean ± S.D