Researchers have found that the age of an elephant can be estimated based on its vocal sounds. It could be a powerful tool for conservation, and one that's less invasive and more cost effective than other methods, such as radiotagging, researchers said. Researchers say that vocal sounds helped them distinguish infants, calves, juveniles, and adults with 70 per cent accuracy and youngsters (infants/calves) from adults with 95 per cent accuracy.