The 'Booming Dune' phenomenon (a.k.a. 'Singing Dunes') refers to loud, low frequency (70 - 105 Hz) sound sometimes generated by sand dunesplugin-autotooltip__plain plugin-autotooltip_bigSand dune formation

"Large swaths of Earth’s surface are covered in loose sediment. The grains that make up this sediment form fascinating bedforms from meandering riverbeds to wavy dunes, whose shapes are constantly changing as water or air currents move the grains.

Although many qualitative accounts of this booming phenomenon have been made, there is no accepted scientific explanation yet for the underlying physics. Furthermore, it is still unknown why only certain dunes boom and others with similar characteristics remain silent."

Source : Professor Nathalie Maria Vriend,(independent researcher for the Royal Society) Booming Sand Dunes [archived]

It seems likely to be related to the Squeaky Sandplugin-autotooltip__plain plugin-autotooltip_bigSqueaky Sand

Sand on some beaches and dunes emits a distinct 'squeaking' sound when moved under pressure - e.g. by walking on it Videos here

It only affects certain types of sand - more rounded and drier grains generally don't squeak (as much). The underlying acoustic mechanism is as yet undiscovered.phenomenon - which is also unexplained.

For a sound recording, see this page this page of the Sonic Tourism website.

A description is provided in Uwe George's In the Deserts of this Earth (1978), pp. 25-26:

Another strange feature of the sandy wastes that to this day has not been fully explained is an auditory phenomenon - a rarely heard booming. It has been described by the British geologist R. A. Bagnold, who encountered it while he was studying dunes in southwestern Egypt, 300 miles from the nearest habitation. "On two occasions it happened on a still night, suddenly - a vibrant booming so loud that i had to shout to be heard by my companion. Soon other sources, set going by the disturbance, joined their music to the first, with so close a note that a slow beat was clearly recognized. This weird chorus went on for more than five minutes continuously before silence returned and the ground ceased to tremble." Bagnold was never able to find a satisfactory explanation for the phenomenon.