Earsand

Earsand is a fictional granular material described in speculative fiction and design studies as a sand-like compound with specialized acoustic properties intended for use in ear-level devices and sound-damping systems. In the imagined setting, earsand consists of microgranules that interact with both airborne sound and body-conducted vibrations to shape the frequency response of the ear and nearby equipment.

The name combines "ear" and "sand," reflecting its proposed form and application. The term is used in world-building and theoretical design projects rather than in real-world science.

Earsand grains are described as silica-based particles coated with a flexible polymer binder. Typical particle sizes range from tens to hundreds of micrometers. The material is said to be moisture-tolerant and tunable in stiffness, enabling adjustable damping and selective acoustic filtering. In many depictions, earsand is processed into porous matrices or micro-reservoirs that can be integrated into devices near the ear canal.

In the fiction, earsand is manufactured by combining extracted silica with biocompatible polymers and then calibrating the pore structure to achieve targeted attenuation of sharp sounds while preserving conversation-level frequencies. Safety and biocompatibility are usually assumed within the narrative context, though no real-world testing exists.

See also: acoustic metamaterials, granular materials, hearing protection.