Modeling sound propagation in the head of toothed whales

Toothed whales, including species such as porpoises, dolphins, orca, and sperm whale, possess highly specialized anatomical structures in the head to support their biosonar systems - echolocation - through millions of years of evoluation. These animals have the remarkable ability to detect and track small targets over long distance and discriminate between minute differences between targets using echolocation, with performance often surpassing that of current human-made sonar systems. However, many questions remain in how exactly the unusual anatomical structures in the head of toothed whales are orchestrated to support such performance.

As part of a Multidisciplinary University Research Initiative (MURI) project, we use finite element modeling techniques in combination with volumetric representations derived from computed tomography (CT) scans to predict the head-related transfer functions (HRTFs) of a dolphin head. The HRTFs summarizes the influence of the head to sounds propagating to the ears. We use HRTFs as a biologically meaningful proxy to provide a physics-based mechanistic understanding of the sound transduction processes.

Funding: Office of Naval Research, Multidisciplinary University Research Initiative (MURI) program