Low frequencies
Elephants are capable of hearing at low frequencies and are most sensitive at 1 kHz. Elephant ears have thick bases with thin tips. The ear flaps, or pinnae, contain numerous blood vessels called capillaries. Warm blood flows into the capillaries, helping to release excess body heat into the environment. This occurs when the pinnae are still, and the animal can enhance the effect by flapping them.
Kieron Nelson 2015 "Vanishing Cultures Photography" All rights reserved