American Acoustical Biologist
A week’s observation of baby elephants at the Washington Park Zoo in Portland, Oregon led scientist Katy Payne to leave her 15-year study of the sounds of humpback whales to begin studying elephants.
Sitting by the elephant enclosure with a male Asian elephant on one side of a high concrete wall and a female on the other, Payne reported that while she heard no sound, she felt a disturbance of sorts. She described it as a “throbbing in the air and pressure on my chest.” With her expertise in animal sounds, Payne suspected that what she was feeling was a rumbling sound that was so low that it couldn’t be heard. She came back the next day with a special tape recorder and saw that it was picking up very low frequency sound (called infrasonic sound) that is inaudible to the human ear.
Over time, she and other researchers determined that elephants make infrasonic calls to one another from great distances. Depending on the atmosphere of the savanna at any given time, the sounds may actually travel as far as 300 km (approx 186 miles).
This provided an important answer for researchers who had long wondered how elephants separated to look for food but seemed to coordinate to re-gather their family when it is time to move on. (Elephants eat up to 500 pounds of plants a day so each animal needs to graze over a wide territory.)
Since this discovery, she began recording elephant sounds in Africa and in America and she formed a not-for-profit group the Elephant Listening Project that is attached to Cornell University. She has been organizing her research into elephant sounds in such a way that researchers will have a dictionary of sorts to better understand elephant communication. The project also keeps track of the size of the elephant population as well as variations in behavior.
As a result of Payne’s discovery, other researchers have investigated other species to see if they, too, have hidden methods of communication. It has been determined that both crocodiles and hippopotami also use sound below the audible range.
Payne is no longer the primary supervisor of the Elephant Listening Project, but she continues to write and lecture about animal communication and is still connected with the Bioacoustics Research Program at the Laboratory of Ornithology at Cornell University. (The Laboratory of Ornithology is the department home for the study of bird and animal sounds.)