Several interrelated family groups may inhabit an area and know each other well. When they meet at watering holes and feeding places, they greet each other affectionately. Smell is the most highly developed sense, but sound deep growling or rumbling noises is the principle means of communication. Some researchers think that each individual has its signature growl by which it can be distinguished. Sometimes elephants communicate with an ear-splitting blast when in danger or alarmed, causing others to form a protective circle around the younger members of the family group.
Elephants make low-frequency calls, many of which, though loud, are too low for humans to hear.