Directional hearing in sharks and other fishes

Abstract

Art Myrberg and his co‐workers were among the first biologists to obtain clear evidence that predatory sharks are able to locate sound sources at long distances. Previous experiments had shown that elasmobranches were relatively insensitive to sounds, and it had been suggested that fish were incapable of determining the direction of a sound source in the far field. It was subsequently shown that fish could discriminate between sounds from spatially separated sources in the horizontal and median vertical planes. They could even distinguish between identical sound sources at differing distances. It has been suggested that fish determine direction using particle motion detectors, the otolith organs of the inner ear. An array of vector detectors is capable of detecting the axis of propagation, but as they are inherently bidirectional there remains a problem in detecting the actual direction of the source. This paper considers the proposal that the ambiguities are resolved by phase comparison between the vector detectors and other detectors responding to the sound pressure incident upon the gas‐filled swimbladde.