Which statement best describes sound intensity?

Sound intensity is defined as the power per unit area carried by a sound wave, and it is directly related to the amplitude of the sound wave. The intensity increases as the amplitude increases; this is because greater amplitude means that the sound wave carries more energy, which translates to a higher intensity. Therefore, as a sound wave's amplitude increases, the loudness of the sound perceived also increases, making this relationship critical in understanding how we perceive sound intensity.

In contrast, the frequency of the sound wave affects pitch but not intensity, which rules out any connection between intensity and frequency. Similarly, the distance from the source plays a significant role in how sound intensity is experienced—sound intensity decreases with distance because the energy spreads over a larger area as it travels, making the statement about independence from distance incorrect. Lastly, pitch is determined by frequency, not intensity, further emphasizing the relationship between amplitude and intensity as the key concept in this context.