The amplitude of a sound wave generally decreases with increasing distance from the source. This phenomenon is known as the "inverse square law" of sound propagation.
According to the inverse square law, the intensity (power per unit area) of a sound wave decreases proportionally to the square of the distance from the source. Since the amplitude of a sound wave is related to its intensity, this means that the amplitude of a sound wave decreases with distance.
Mathematically, the relationship between amplitude and distance (assuming spherical spreading) can be expressed as:
A ∝ 1 / r
Where A represents the amplitude of the sound wave, and r represents the distance from the source. This means that as the distance (r) increases, the amplitude (A) decreases.
It's important to note that other factors can also affect the amplitude of a sound wave, such as obstacles, reflections, and absorption in the medium through which the sound travels. However, in a free field condition (without significant obstructions or reflections), the inverse square law governs the amplitude-distance relationship.