A Quick Look At Sound Waves
In physiology, sound is produced when an object’s vibrations move through a medium until they enter the human eardrum. In physics, sound is produced in the form of a pressure wave. When an object vibrates, it causes the surrounding air molecules to vibrate, initiating a chain reaction of sound wave vibrations throughout the medium. While the physiological definition includes a subject’s reception of sound, the physics definition recognizes that sound exists independently of an individual’s reception. You may recognize this section from our blog post, “What is a Sound Wave in Physics?” Keep reading for a more in-depth look at sound waves. Everyone is familiar with the concept of sound waves, but sound can also travel as a set of pulses; these are the two primary patterns that sounds take as they travel. When these pressure variations travel through a specific material (usually air), they push and compress the molecules in their path and take a very specific shape.
Those pulses spread as they travel, growing wider and taller with time. As this cone expands, the pressure weakens and the sound becomes diluted or less powerful, which affects how clearly we are able to hear them. But that original “shape” remains.
With this mental image, it’s easy to see how “sound” quickly becomes “noise.” Crowded streets are full of competing pulses, while a single sound travels differently through air as compared to another medium like water or rock.
Music is an even more complicated set of audio signals because it can consist of sounds from multiple sources, at multiple frequencies, and sometimes even from multiple directions. And the way sound travels becomes even more complex when we think about hearing range, sound diffusion, and how different sources create different sound wave shapes.