Sound waves travel as longitudinal waves. Longitudinal waves are characterized by the displacement of particles in the medium parallel to the direction of wave propagation. In the case of sound waves, the particles of the medium (such as air, water, or solids) vibrate back and forth in the same direction as the wave is traveling.
To visualize a longitudinal sound wave, imagine compressing and expanding a coiled spring. When you compress the coils of the spring, it creates areas of higher pressure or compression, and when you expand the coils, it creates areas of lower pressure or rarefaction. This compression and rarefaction pattern propagates through the medium, forming a series of compressions and rarefactions that represent the sound wave.
In contrast to longitudinal waves, transverse waves involve particles oscillating perpendicular to the direction of wave propagation. Sound waves, however, do not exhibit this type of particle displacement, making them distinct as longitudinal waves.