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How is a sound wave like a compression moving through a coiled spring?

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Watch a suspended vibrating spring to learn about the propagation of sound waves — sound Learn about the propagation of sound waves from a point source by observing the motion of a suspended vibrating spring.

A sound wave is classified as a longitudinal wave, meaning the mechanical vibration occurs in the same direction as the wave's propagation.12

This process is directly analogous to a coiled spring: when you squeeze several turns of the spring together to form a compression and release them, that disturbance travels along the length of the spring. Similarly, sound propagates through a medium like air by creating alternating regions of high pressure (compressions) and low pressure (rarefactions).123

Just as the coils of the spring "push" and "pull" at one another to transmit the impulse, air particles vibrate back and forth around their equilibrium positions, disturbing neighboring particles to pass the wave forward. In both cases, the particles of the medium move along the axis of propagation rather than perpendicular to it.132