I've listened to sand dune rumble during a school trip when I was in 8th grade in Saudi Arabia
, perhaps out of ignorance, or amusement, our teacher ascribed the drum beats we heard to Jinns
. Also ascribing it to evil spirits, Marco Polo
stated in the 13th century, "at times fill the air with the sounds of all kinds of musical instruments, and also of drums and the clash of arms."
According to research carried out by Bruno Andreotti
from the University of Paris-7
, his proposal is the sounds come from vibrations in the sand bed that have been excited by collisions between hot and dry grains of sand.
The French physicist took his equipment from Paris to the Atlantic Sahara
, which contains more than 10,000 crescent shaped dunes known as barchans
. The wind in the desert can erode the back of these dunes, causing sand to build up at the top of the dune.
An avalanche takes place and the dunes start to "sing". There are about 35 known locations in the world where the dunes "sing". The sounds produced can be heard up to 10 kilometers away and resemble a drum that can last up to 15 minutes. The sounds can be as loud as 105 decibel
s and have frequencies between about 95 and 105 Hertz