Feasibility of spectral-element modeling of wave propagation through the anatomy of marine mammals

: This study introduces the first three-dimensional spectral-element method (SEM) simulation of ultrasonic wave propagation in the head of a bottlenose dolphin (Tursiops truncatus). Unlike traditional finite-element methods (FEM), which struggle with high-frequency simulations because of costly linear-system inversions and slower convergence, SEM offers exponential convergence and efficient parallel computation. Using computed tomography data, we developed a detailed hexahedral mesh capturing key anatomical features, such as acoustic fats and lower jaws. Our simulations of plane and spherical waves confirm SEM's effectiveness for ultrasonic time-domain modeling. This approach opens new avenues for marine-bioacoustic research, including echolocation, the biophysics of hearing and sound generation, and assessments of anthropogenic underwater noise. By overcoming FEM's limitations, SEM provides a powerful scalable tool to test hypotheses in dolphin bioacoustics, with significant implications for conservation and understanding marine-mammal auditory systems under increasing environmental challenges.