Sound refers to the vibrations that travel through the air or another medium and can be heard when they reach a person's ear. It is produced by an object vibrating, which then causes the air particles around it to vibrate as well.
Related terms
Frequency: The number of sound waves per second. Higher frequency results in higher-pitched sounds.
Pitch: How high or low a sound is perceived. High pitch corresponds to high-frequency sound waves, while low pitch corresponds to low-frequency sound waves.
Amplitude: The intensity or loudness of a sound wave. Higher amplitude produces louder sounds, while lower amplitude produces softer sounds.