What is the term for the substance through which a mechanical wave travels?

The substance through which a mechanical wave travels is known as the wave medium. This term refers to any material or environment that enables the propagation of mechanical waves, such as sound waves or seismic waves. Mechanical waves require a medium—such as air, water, or solids—to transmit energy. The characteristics of the medium significantly influence the wave's behavior, including its speed and amplitude.

For instance, sound waves travel faster in solids than in gases due to the closer proximity of the particles in solids allowing them to transmit the energy of the wave more efficiently. Understanding the role of the wave medium is crucial in fields ranging from acoustics to geophysics, as it helps explain how waves interact with different materials and how they can be manipulated or measured in various scientific applications.