Compression waves, which are generally referred to as longitudinal waves, follow the motion of the occurring wave and do not displace mass. When the wave becomes compressed, its density increases.
When a compression wave travels, it follows along the path of the wave, but will never surpass the length of it. Additionally, the wave follows the same vibration pattern as its successor. These waves are often pressurized as seen with sound waves. When the wave compresses and reaches a range of pressures, sound is made audible. People are susceptible to hearing sounds of various pressures and densities as made by the compression waves.