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