Auditory Computations for Biosonar Target Imaging in Bats

Abstract

Bats are nocturnal flying mammals classified in the order Chiroptera. These animals have evolved a biological sonar, called echolocation, to orient in darkness—to guide their flight around obstacles and to detect their prey (Griffin 1958; Novick 1977; Neuweiler 1990; see Popper and Fay 1995). Echolocating bats broadcast ultrasonic sonar signals that travel outward into the environment, reflect or scatter off objects, and return to the bat’s ears as echoes. First the outgoing sonar signal and then the echoes impinge on the ears to act as stimuli, and the bat’s auditory system processes the information carried by these sounds to reconstruct images of targets (Schnitzler and Henson 1980; Simmons and Kick 1984; Suga 1988, 1990; Simmons 1989; Dear, Simmons, and Fritz 1993; Dear et al. 1993).