Rustle noise
Rustle noise is noise consisting of aperiodic pulses in a Poisson distribution, characterized by the average time between those pulses, known as rustle time (such as the mean time interval between clicks of a Geiger counter). Rustle time is determined by the fineness of sand, seeds, or shot in rattles, contributes heavily to the sound of sizzle cymbals, drum snares, drum rolls, and string drums, and makes subtle differences in string instrument sounds.