Diving deeper into dolphin echolocation beam formation – 3D acoustic field propagation models of internal beam formation based on in vivo computer tomography images

Toothed whale echolocation has been studied since the 1950s. However, it is still unknown how the echolocation beams are created. This study will answer this. It is known that the properties of the beams can be changed dramatically but gradually from click to click. How this control is achieved is unknown.

However, it is thought the exotic material properties and intricately shaped tissues in the animal´s foreheads are utilized.

This study will find out how the mechanical and acoustical properties of bottlenose dolphin (Tursiops truncatus) head tissues form the acoustic field, generated inside of the animals´ heads, into a forward-projected beam.

The method will be to compare acoustic echolocation recordings with output from 3D finite element (FE) computer models of the head of a bottlenose dolphin.

The acoustically and structural mechanically coupled wave propagation model will be based on world unique in vivo computer tomography (CT) scans of an individual that also echolocation measurements have been obtained from.

The model will be state-of-the-art as it will apply individual material properties to each mesh element within the model, and be able to model the full acoustic frequency bandwidth of dolphin echolocation.

The fundamental research questions are; how do dolphin anatomy form sonar beams and what target information can they return to the animal? The answers will be mined for biomimetic concepts for technology and used for toothed whale noise resilience research.