Yes, the intensity of a sound wave changes as it travels from its source to the listener. The change in intensity is primarily due to the phenomenon of geometric spreading or spreading loss.
Geometric spreading refers to the dispersion of energy as a sound wave propagates outward from its source in a three-dimensional space. As the sound wave expands, the same amount of energy is distributed over an increasingly larger surface area. Consequently, the intensity (power per unit area) of the sound wave decreases as the distance from the source increases.
According to the inverse square law, the intensity of a sound wave is inversely proportional to the square of the distance from the source. This means that as the listener moves farther away from the source, the intensity decreases by a factor of the square of the distance.
For example, if you double the distance from the source, the intensity at the new location would be one-fourth (1/2^2) of the original intensity. If you triple the distance, the intensity would become one-ninth (1/3^2) of the original intensity, and so on.
It's important to note that while geometric spreading is the primary factor causing a decrease in sound intensity, other factors such as absorption, scattering, and reflection can also contribute to changes in intensity as the sound wave travels through a medium. These factors may cause additional losses or modifications to the sound wave's energy.