In daily life, the sound of mixing flour is almost undetectable; the sound of hitting the sandbag is dull; The maracas used as a musical instrument has a bright and loud sound; the sound is clear and melodious. The sound produced by the earth's particles under the disturbance of external forces is affected by many factors and produces different sound characteristics.
So I wander which and how different factors actually affect the sound made by the collision of tiny solid particles such as sand. And I'm eager to learn the mathematical expressions between the sound and different physical factors.
P.S. The sound here is not restricted to a single factor; and the physical factors here should only be related to the particle itself, the container or the outer force that causes the collision.