What type of wave is primarily used to describe sound waves?

Sound waves are primarily described as longitudinal waves because they propagate through a medium by causing the particles of that medium to oscillate back and forth in the same direction as the wave travels. In a longitudinal wave, compressions and rarefactions occur: the particles are compressed together in areas of compression and spread apart in areas of rarefaction. This motion allows sound energy to be transmitted through various materials, including solids, liquids, and gases.

While sound can also be categorized as a mechanical wave since it requires a medium to travel, the specific characteristic that defines sound waves is their longitudinal nature. Therefore, when identifying sound waves, the key feature is the longitudinal oscillation of particles, making it clear that this is the correct classification.