In another thread, "crepitation" reminded me of singing sand. Some sandy areas are much more noisy underfoot than
others, probably depending on how much the sharp edges of
the silicon crystals has been rounded by wave or wind action. In some areas, just the wind can cause the noise.

Singing sand

Singing sand is sand that emits sounds of either high or low frequency under pressure. The sound emission is usually triggered by wind passing over dunes or by walking on the sand. The sound is generated by shear stress.

Certain conditions have to come together to create singing sand:

The sand grains have to be round and between 0.1 and 0.5 mm in diameter
The sand has to contain silica gel
The sand needs a certain humidity
The most common frequency emitted seems to be close to 450 Hz.

Other sounds that can be emitted by sand have been described as "roaring" or "booming".


External links
Booming sand

... Listen to the age old story of The shifting, whispering sand ...

Yes it always whispers to me
Of the days of long ago
When the settlers and the miners
Fought the crafty Navajo
How the cattle roamed the valley
Happy people worked the land
And now everything is covered
By the shifting, whispering sand

Oh the miner left his buckboards
When he worked his claims that day
And the burro's broke their halters
When they thought he'd gone to stay
How they found the ancient miner
Lyin dead upon the sand
For months they could but wonder
If he died by human hands

So they dug his grave and laid him
On his back and crossed his hands
And his secret still is hidden
By the shifting, whispering sands

This is what they whispered to me
Way out in the quiet desert air
Of the people and the cattle
And that miner lying there

If you want to learn his secret
Wander through this quiet land
And I'm sure you'll hear the story
Of the shifting, whispering sand

... The shifting, whispering sand...

The sands along the shore at Tulum, in Quintana Roo, Mexico make noise when walked upon. It is a very fine white sand, almost as fine as talcum powder. Not a good thing in a wind storm, sleeping in a thatched hut. You wake up in the morning and you and everything in the hut resemble an emery board.