Fig. 3. Mean (± s.e.m.) hearing thresholds of the Lusitanian toadfish under laboratory conditions (baseline; black line) and in the presence of ambient noise (blue line) and ship noise (red line). Dashed lines of same colour show the cepstrum-smoothed sound power spectra for the respective noise types used during audiogram determinations. Asterisks indicate statistically significant differences between the ambient noise and baseline (unpaired t-tests) as well as ambient and ship noise (paired t-tests); *P<0.007 and **P<0.001). N=9, baseline; N=6, ambient and ship noise audiograms.