Heterotrophs hope this helps.
Sound waves are both compressional and longitudinal, (although we frequently draw them as transverse waves).
Longitudinal waves are where the particles of matter collide into one another, pushing them into the next and then oscillating back. This is how sound travels. This is also why sound can only travel through a medium, it cannot travel through a vacuum, as is shown here:
There are two sets of nerves in your skin. The first type are somatosensory neurons that send sensory information to your central nervous syste. The second set consists of autonomic fibers that control smooth muscle in the skin and the blood vessels in the skin.