Is Sound Just Vibrations?
When we consider what defines sound in a physics context, it can be tempting to assume sound is just vibrations. While partially true, sound is much more complex than simple vibrations. When a sound source vibrates, it produces sound energy that travels through particle disturbances in the medium, effectively transmitting the sound. As a sound wave moves through a medium, it creates high and low pressure differences called rarefactions and compressions. These differences are the result of particles within the medium shifting from their original states and causing other particles to compress or expand as a result.
While a vibrating source creates sound energy, pressure differences make up the sound wave. Specific patterns of rarefactions and compressions are what give sounds their distinct characteristics, and ultimately, allow us to differentiate between noises, melodies, and other sounds.