If a tree fell in the woods, would there be a sound? The answer to that question is often debated and it depends on how you define the word sound. In this class, however, we will take an objective look at the nature of sound, rather than just the definition of the word. That way, we can argue the science not semantics.
So, then, what is sound? Sound waves are produced by vibrations within objects. It is simple to see this in a piano or a guitar as the sounds are produced by vibrating strings. Even your voice is caused by the vibrations of your vocal chords. These vibrations cause disturbances in the medium around them causing longitudinal pressure waves. As you progress through this lesson, you will learn more about the nature of sound so you can speak objectively and scientifically if ever anyone asks you that question.
Question
In a crowded room, you clap your hands. Why can everyone in the room hear you?
The wave pulse that was created by the clapping hands goes out in three dimensions. This is often depicted in a diagram as a point source with circles (representing the sound waves) moving away from that source, though the actual movement is spherical.
