See link for audio report, which begins at 16:50.
Report on new research from Oxford University and the charity Save the Elephants which created 3 types of seismic activity in the Samburu and Buffalo springs reserves in Kenya from a loudspeaker partly buried in the earth. They played recordings of elephants computer-generated white noise and human sounds while they did not react to the elephant recordings the animals froze scanned the horizon and then fled when they heard the man-made noises.
The lead researcher at Oxford University, Dr Beth Mortimer, says: ‘We’ve shown that vibrations beyond those generated by elephants are important to elephants. They respond to human generated seismic vibrations and the associated with risk. This means we need to think carefully about the type of noise that we are putting into the ground so not just light pollution or acoustic noise but seismic noise generated by humans because these are important for elephants and have potential impacts for their conservation.”