The sense of hearing, otherwise known as audition, allows people to interpret the frequency, amplitude, timbre, and origin of sound waves. A sound wave is essentially moving air, but sound is capable of traveling through many other mediums such as water, metal, concrete, etc. Contrary to what you may think, hearing is a purely physical process. Sound requires a physical medium to travel through to reach your ear. There’s no sound in space because there’s no air or other physical medium for sound waves to move through.