Abstract:

The singing sand dunes in Mulei County, Xinjiang, are renowned for their unique sound and environmental conditions, earning the title of “the first sound in the world, Wooden Barrier Singing Sand Mountain.” Influenced by regional fold faults, sand transport, and the stabilization of sand particles from the surrounding deserts and Gobi plains, these dunes produce a unique sound due to their well-sorted, bright, and clear desert sand. This study examined the environmental and material characteristics of Mulei’s singing sand, including its acoustic properties, particle size distribution, and other factors involved in its formation. A comparative analysis of the singing sands of the Badain Jaran Desert and Dunhuang highlighted the relationship between the topography and sound production. This study scientifically and systematically explains the material sources of the singing sand and investigates the influence of particle size on the acoustic properties by measuring the sound produced by sand particles of varying sizes. The findings reveal the following: (1) The mineral composition of Mulei’s singing sand is primarily quartz, similar to those in the Badain Jaran Desert and Dunhuang, but with significantly different quartz and feldspar contents. Mulei’s singing sand has a considerably higher feldspar content and a relatively lower quartz content than those of the other two regions. The sand’s acoustic properties are independent of specific proportions of quartz and feldspar particles in the mineral composition. (2) The grain size composition of Mulei’s singing sand is predominantly medium sand, exhibiting a coarser texture than those of the Badain Jaran Desert and Dunhuang, although it is well-sorted. This coarsening trend is identified as a factor contributing to the distinctive acoustic characteristics of the Mulei’s singing sand. (3) The surface of Mulei’s singing sand features typical aeolian impact craters and chemical dissolution pits formed by temperature fluctuations and wind erosion, creating a porous, rounded surface structure similar to that of the singing sands in the Badain Jaran Desert and Dunhuang, which acts as a “resonance box,” influencing the sound production of the singing sand. (4) The particle size of the singing sand significantly affects its acoustic characteristics. Among these, medium-sized sand particles produce the highest pitch, loudest volume, and the brightest, sharpest sound quality compared to other particle sizes.

Key words: Mulei singing sand, environmental conditions, mineral composition, particle size distribution, surface structure