Localization of sounds and targets in air and water by echolocating animals

Abstract

Mammals that use echolocation, or biological sonar, to perceive the locations of objects in their environments have unusually acute capacities for localizing sound (echo) sources and for perceiving reverberation since they rely upon echolocation for spatial perception. Both bats in air and porpoises in water determine the distance to targets from the arrival time of echoes. The sonar signals which they emit are directional, with the possibility that porpoises may transmit different waveforms as well as different signal amplitudes in different directions. The hearing of echolocating animals is also directional, with reception through the external‐ear system in bats and through the lower jawbone in porpoises. Directional hearing provides binaural cues for horizontal localization of targets. In bats, the external ear has directional amplitude and phase responses which the bat uses for vertical localization of targets. In porpoises it is possible that the transmitted waveform contributes to vertical localizat...