What Is Sound?
Breaking that down into layman’s terms, sound is what happens when something vibrates. The vibration may be imperceptible to sight and touch, but it still happens. When it happens, that vibration causes a change in the air pressure around the object. When you hear sound, what you’re hearing is not actually the vibration of the object. Instead, what you’re hearing is the air pressure displacement. It’s an odd concept, but there’s plenty of science backing up the idea of sound waves.
There are two ways to define the term “sound”, and both are completely correct. There’s the definition in physics, which is that sound is a vibration that causes displacement of air or water pressure. In physiology, sound is the reception of those waves and how the brain perceives them. In truth, these definitions are simply two sides of the same coin.
To see this in action, you can take any kind of hard, flexible object. Try making it vibrate in various ways. Hold it tightly and don’t let it vibrate as much. Hold it more loosely and allow it to vibrate more. You can watch the vibrations and hear the differences in the sounds that it makes. You can see this sort of thing further in a variety of bands that make a habit of playing sound on odd objects. One such band is named Savage Aural Hotbed, and they’re well known for making interesting music with oil drums, power tools, and other household objects.