Sound propagates through a medium via masses connected by intermolecular forces.

Evidence

Consider the simple mechanical model of the propagation of sound through some physical medium, shown in Figure 1.1. This shows a simple one-dimensional model of a physical medium, such as air, which we call the golf ball-and-spring model because it consists of a series of masses, for example, golf balls, connected by springs. The golf balls represent the point masses of the molecules in a real material, and the springs represent the intermolecular forces between them. If the golf ball at the end is pushed toward the others, then the spring linking it to the next golf ball will be compressed and will push at the next golf ball in the line, which will compress the next spring, and so on. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 50

Categorization

• DEFINE: Introduces the golf ball-and-spring mechanical model, the foundational visual metaphor for sound propagation.
• corroborated: 2 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 50
• XREF: connects to: Medium-specific sound transmission across solids, liquids, and gas yields distinct sonic ecologies. — Almo Farina, Soundscape Ecology: Principles,…, 52