From the very beginning of time, the Planet Earth was not a silent place. And, as it was increasingly populated by living beings, these quickly learnt that sounds constitute an excellent means of communication.
African elephants emit a wide range of vocalisations to communicate with each other, but one type is particularly interesting – the very low frequency or infrasonic calls, which the human ear cannot perceive.
These infrasonic signals have a longer wavelength than high frequency sounds, and so are not affected by obstacles such as leaves or grass. They are therefore ideal for communication over long distances.
On the savannah or in the jungle, elephants can hear a bellow or loud trumpeting only up to a few hundred metres away, while an infrasonic sound is audible to another elephant at a distance of several kilometres.
These calls are very useful when the female comes into heat, given that this only happens for three days every four years. As the males and females live apart from each other, often kilometres away, the bulls hear the call and have just enough time to reach the female before it is too late.
In Africa, the groups of humans also quickly discovered an efficient system for transmitting calls over long distances.
The percussion of drums is capable of communicating surprisingly complex messages over many kilometres, across jungle or plain alike.
But it is used above all to convey a message or important announcement which all the members of the group must hear, no matter how far away they are; wars, weddings or meetings, no one can claim that they weren’t informed if the message is sent by tom-tom.
The system of percussion is also used on the Island of New Guinea, and in many others in Indonesia.
The rhythm and cadence inform that an important initiation ceremony is about to take place, and must be attended by representatives of neighbouring villages.