The sounds, which are are as low as the lowest notes of a pipe organ, can be heard by other elephants from several miles away. But while their existence has been known for many years, the mechanism by which they are produced wasn't clear.
Now, though, researchers at the University of Vienna have removed the larynx from an elephant - which died of natural causes, they hasten to point out - and blown air through it to find out.
When they manually placed the vocal folds into the 'vocal' position, they found they produced periodic, low-frequency vibrations that match infrasounds in all details.
It shows that the sounds don't originate, as many scientists suspected, in the same way as a cat's purr, by tensing and relaxing the muscles of the larynx. Instead, they're produced in the same way as human speech, with the low frequency caused by the much lager size of the larynx. Read the full report here.
Source: by Emma Woollacott, TG Daily.
