Elephants make many sounds, including low frequency rumbles, barks, snorts, cries, roars and chirps, according to ElephantVoices. The low-frequency rumble is used most often by elephants.
Defenders of Wildlife says that this rumble travels quickly over the ground and that the elephants receive the messages through their feet and trunks. Social groups and potential mates communicate in this manner.
Animal Fact Guide notes that elephants also have good auditory localization skills that allow them to judge the distance between themselves and other elephants by listening to the pitch of the calls. Communication is vital to elephants because their survival depends on their social groups.