Acoustic processes in an echolocating bottlenose dolphin’s (Tursiops aduncus) head using a finite element model

Abstract

Bottlenose dolphins (Tursiops aduncus) are a well-known species using broadband echolocation signals for searching prey and spatial orientation. In this study, the computed tomography (CT) scan data were obtained to set up a two-dimensional finite element model. In the vertical plane, the acoustic field on the animal’s forehead and the far field transmission beam pattern of an echolocating dolphin were calculated. The simulation results and prior measurement results were consistent qualitatively. The role of the main structures on the sound propagation pathway such as air sacs, melon, skull, and connective tissues was investigated. Furthermore, the signal at the source excitation was investigated. It suggested that the broadband echolocation dolphins may not have the same driving signals at the source excitation as the narrowband echolocation dolphins. The results can help us gain further understanding of the acoustic processes in dolphin’s biosonar.