Which acoustic property is primarily responsible for determining the loudness of sound?

The correct answer is intensity, as it is the acoustic property that primarily determines the loudness of sound. Intensity refers to the amount of energy carried by a sound wave per unit area in a direction perpendicular to that area, which corresponds to how powerful the sound wave is. A higher intensity results in a greater amplitude of sound waves, leading to the perception of increased loudness in human hearing.

Loudness is a perceptual phenomenon that correlates closely with intensity. While frequency and pitch are related concepts, frequency pertains to the number of cycles of a sound wave per second, which influences how high or low a sound is perceived, rather than its loudness. Duration refers to the length of time a sound is heard and does not directly impact the perceived loudness, although sounds of longer duration may be perceived as louder due to sustained attention.

Understanding the role of intensity in sound perception is essential for fields such as audiology and speech science, as it directly relates to how individuals experience different sounds in their environment.