Waves and Sound
Birute Bartkeviciute
Target Group
Brief Description
A lesson about waves,sound and propagation


Waves and sound. Intro. How does sound waves work?

Before you learn how sound equipment works it's very important to understand how sound waves work. This knowledge will form the foundation of everything you do in the field of audio.

Sound waves exist as variations of pressure in a medium such as air. They are created by the vibration of an object, which causes the air surrounding it to vibrate. The vibrating air then causes the human eardrum to vibrate, which the brain interprets as sound.

Sound waves travel through air in much the same way as water waves travel through water. In fact, since water waves are easy to see and understand, they are often used as an analogy to illustrate how sound waves behave.

Sound waves can also be shown in a standard x vs y graph, as shown here. This allows us to visualise and work with waves from a mathematical point of view. The resulting curves are known as the "waveform" (i.e. the form of the wave.)


The wave shown here represents a constant tone at a set frequency. You will have heard this noise being used as a test or identification signal. This "test tone" creates a nice smooth wave which is ideal for technical purposes. Other sounds create far more erratic waves.

Related files

sound_and_waves (6) 2 MB
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