Evoked potential audiogram of the lined seahorse, Hippocampus erectus (Perry), in terms of sound pressure and particle acceleration

Abstract

The hearing sensitivity of the lined seahorse, Hippocampus erectus (Perry), was determined for both sound pressure and particle acceleration using the auditory evoked potential (AEP) technique. Hippocampus erectus demonstrates hearing sensitivity typical of historically characterized hearing generalist fishes, with best sensitivities below 600 Hz and maximum sensitivities of 105.0 ± 1.5 dB SPL (re: 1 μPa) and 3.46 × 10−3 ± 7.64 × 10−4 m s−2 at 200 Hz. The shapes of the audiograms for each modality are similar, suggesting relative similarity in sensitivity between modalities for a given frequency. In light of the importance of broadband sound in the acoustic landscape of this fish’s environment, and broadband conspecific sound production that may be used in intraspecific acoustic communication, audition to broadband sounds was also estimated. Maximum broadband sensitivity at 200 Hz is estimated to be 92.0 ± 1.5 dB SPL (re: 1 μPa) and 7.73 × 10−4 ± 1.71 × 10−4 m s−2.