What term is used to describe the magnitude of sound?

The term that describes the magnitude of sound is "Loudness." Loudness refers to the perception of sound intensity by the human ear. It essentially represents how we perceive the strength of a sound, influenced by both the physical properties of sound waves and the sensitivity of our hearing.

Intensity refers to the physical measure of sound energy per unit area and is often measured in watts per square meter. While intensity relates to the objective measure of sound energy, loudness is more about the subjective experience.

Amplitude, on the other hand, pertains to the maximum extent of a vibration or oscillation in a sound wave, which can influence loudness. However, it is not the term specifically used to describe how loud a sound appears to the listener.

Decibel is a unit of measurement for sound intensity. While it helps quantify loudness, it itself does not define the concept. Therefore, loudness, as the perceived magnitude of sound, is the most appropriate term in this context.