But according to their research, the reason why you can't hear them hum a tune is because the elephant’s infrasound rumble is often too low for the human ear to hear. The low-pitched elephant calls occupy a frequency range below 20
Hertz, which is way to deep for any human to hum. The Daily Mail reports:
Experts had wondered whether, like a cat’s purr, elephant infrasound was generated by muscular 'twitching' movements of the vocal cords.
Instead, it turns out the elephant sounds are made purely by air being blown through the larynx, or voice box, as in the case of a human singer.
The German team carried out laboratory tests on a larynx removed from an African elephant that had died naturally at a Berlin zoo.
Air under pressure was passed through the vocal cords to see if the elephant calls could be reproduced.
So why do elephants hum? Turns out it helps them to communicate over distances of up to six miles, keeping the herds together and to find new mates. Guess this means that these pachyderms truly are the Barry Whites of the animal kingdom.