Finite element modelling of hearing capabilities in the Little Penguin (Eudyptula minor)

Despite increasing concern about the effects of anthropogenic noise on
marine fauna, relevant research is limited, particularly in those
inaccessible species, such as the Little Penguin (Eudyptula minor). In
this study, we collected freshly deceased Little Penguins for dissection
and microCT scans. The head structures, including the ear apparatus, were
reconstructed based on high-resolution imaging data for the species.
Moreover, 3D finite-element models were built based on microCT data to
simulate the sound reception processes and ear responses to the incident
planar waves at the selected frequencies. The received sound pressure
fields and motion (i.e., displacement and velocity) of the internal
ear-related structures were modelled. The synergistic response of ear
components to incident aerial and underwater sounds was computed to
predict the hearing capabilities of the Little Penguins across a broad
frequency range (100 Hz–10 kHz), both in air and under water. Our
predicted data showed good agreement with other diving birds in both the
form and range of auditory sensitivity. This study demonstrates a
promising method to study hearing in other inaccessible animals. The
outputs from this study can inform noise impact mitigation and
conservation management.