low frequency sound

Acoustic (that is, sound) signals are omni directional (i.e. they travel in all directions) and can be broadcast to a large audience of intended and unintended listeners, including those in view and those hidden from view. Being short-lived and deliberate, acoustic signals are useful for giving information about an immediate situation, rather than about a constant state. Through reflection, refraction and absorption, acoustic signals are degraded by the environment in ways that are often very much greater for high frequency sounds than for very low frequency sounds. Elephants are specialists in the production of low frequency sound and in the use of long-distance communication. Check out some good examples on acoustic communication by elephants in article "What Elephant Calls Mean: A User's Guide" published by National Geographic in 2014, based on the work of ElephantVoices.

The range of sounds elephants produce

African elephants produce a broad range of sounds from very low frequency Rumbles to higher frequency Snorts, Barks, Roars, Cries and other idiosyncratic sounds. The most frequently used type of call is the very low frequency Rumble. You can search for, listen to and read about numerous calls and other sounds made by elephants on The Elephant Ethogram: A