3D modeling and animation techniques to elucidate mechanisms of echolocation-based acoustic perception

Abstract

Current models of echolocation focus on the presence of specular acoustic surface reflections or ‘‘glints’’ as the perceptual cues that provide information about object distance and geometry. Using current material and motion 3D modeling techniques for visual animation, we have developed models of common real-world elements that can be detected by bat biosonar. By mapping acoustic reflectivity data from natural and artificial targets onto luminosity, specularity and reflection coefficients for materials and accurate spatial models of these objects, we have generated visual glint-like reflections from object surfaces that are similar to echolocation data. This allows us to create 3D visual animations of echolocation auditory scenes. Using these animations, human observers can integrate object shapes, sizes and movements based on gestalt grouping, particularly when the target moves or the echolocation source is in moving in relation to the target. These types of modeling tools may help elucidate the perceptual phenomena arising from integration of the individual acoustic glint structures that allow bats and other echolocating animals to create complex umwelts from auditory data.