A report in New Scientists say it's a common practice, but elephants react most if the calls they hear come from elephants they know.
Elephants are already known for their ability to emit low-frequency sounds to communicate with herds up to several miles away.
Researchers led by Caitlin O'Connell-Rodwell of Stanford University Medical Center in California also suspected that these rumblings generate seismic waves that travel through the ground, enabling elephants to pick up the signals through their surprisingly sensitive feet.
Her team recorded alarm calls in Namibia and Kenya made by elephants when lions were lurking.
They then played just the seismic portion of the sound through the ground to herds at watering holes in Namibia.
The elephants "reacted dramatically, first freezing and then clumping in tight groups, with babies in the middle," the British weekly reports in next Saturday's issue.
But the farther the elephants lived from the herd which made the call, the less they reacted.
The study is to be published in the Journal of the Acoustical Society of America, New Scientist says.