Erratum to: Amphibious auditory evoked potentials in four North American Testudines genera spanning the aquatic–terrestrial spectrum

Erratum to: J Comp Physiol A (2015) 201:1011–1018 DOI 10.1007/s00359-015-1031-6

Additional measurements of the pressure gradient using two hydrophones revealed an error in the particle acceleration reported for 10 cm below the surface in Table 1. At this location, particle accelerations were in fact 4.5–8.5 dB lower than at the surface, rather than 12–16 dB lower. After repeated measurements of the test chamber under identical conditions, we could not replicate the reported values at 10 cm below the surface, but found no errors in our calculations. Therefore, we attribute the error to a lowered recording setting on the digital recorder during acquisition. The figure and table below show 3 additional measurements taken at the surface and at 10 cm below the surface in relation to the originally reported values. Values represent the mean and s.e.m of the particle acceleration combined across 3 measured axes. All measurements were taken around a center point calibrated to a sound pressure level of 126 dB re 1 µPa. The results do not change our interpretation of comparisons between species, since it indicates that the sound field experienced by Sternotherus spp. was more similar to the conditions for T. carolina carolina and T. scripta tested at the surface.

Table Particle acceleration in dB re 1 m/s² for original and additional measurements at the surface and 10 cm below the surface

	Surface (original)	Surface (additional measurements)	10 cm deep (original)	10 cm deep (additional measurements)
100 Hz	−17.73	−20.60	−33.51	−26.87
200 Hz	−21.22	−19.99	−34.38	−28.46
300 Hz	−21.18	−20.43	−34.24	−26.10
400 Hz	−19.29	−19.57	−32.32	−25.12
500 Hz	−19.02	−20.29	−31.57	−25.19
600 Hz	−19.41	−16.82	−32.47	−25.18
700 Hz	−19.66	−17.01	−31.44	−24.05
800 Hz	−18.84	−19.26	−31.28	−23.79