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arXiv · 2508.15739

Pseudo-spectral model of elastic-wave propagation through toothed-whale head anatomy, and implications for biosonar

Fawad Ali·Carlos García A.·Aida Hejazi-Nooghabi·Lapo Boschi
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Abstract

The sound-localization and, in particular, biosonar system of toothed whales is exceptionally performant. How this is achieved is not clear, given that: (i) toothed whales have no pinnae; (ii) while their auditory pathways have been studied in detail, no specific feature apparently replacing the pinna has been identified. In this study, we employ a pseudo-spectral time domain (PSTD) numerical scheme to model three-dimensional elastic wave propagation through a toothed-whale head including soft tissues. Computed tomography (CT) scans were utilized to build a three-dimensional velocity-density model of the specimen's head, parametrized on a high-resolution $1.11$ mm voxel grid. We first validate our wave propagation solver, identifying a range of frequencies and spatial scale lengths where the PSTD scheme captures the complexities of elastic wave propagation through toothed-whale anatomy. We next focus on the toothed whale's ability to locate sources on the median plane, where the role of anatomy is crucial. A 45 kHz central frequency burst (dolphin-like click) was modeled and directed at elevation angles from $-90^\circ$ to $+90^\circ$ in $5^\circ$ steps along the midsagittal plane. We find that the incoming sound can be localized, via correlation, from the reverberated portion of the time-domain waveforms recorded at the tympano-periotic complex locations.

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Fawad Ali, Carlos García A., Aida Hejazi-Nooghabi, Lapo Boschi. 2025-08-21. Pseudo-spectral model of elastic-wave propagation through toothed-whale head anatomy, and implications for biosonar. https://doi.org/10.1121/10.0041770

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