The path followed by a sound wave from its source to your ear is generally not a straight line but rather a curved or indirect path. This phenomenon is due to the way sound waves interact with the surrounding environment and are affected by various factors, including obstacles, temperature gradients, and the presence of different mediums.
When a sound wave propagates, it spreads out in a spherical or cylindrical shape, with the source as the center. As the wave encounters obstacles or objects in its path, such as buildings, trees, or other structures, it can undergo reflection, diffraction, and refraction.
Reflection: Sound waves can bounce off surfaces, such as walls or the ground, and change their direction. This reflection can redirect the sound wave along a different path.
Diffraction: Sound waves can bend or spread out as they encounter obstacles or pass through openings. This bending allows sound to reach areas that may be obstructed from direct line-of-sight propagation.
Refraction: Sound waves can change their direction as they pass through different mediums with varying properties, such as air layers with different temperatures or densities. The change in the speed of sound through these mediums can cause the sound wave to refract or bend.
Moreover, the speed of sound is not constant throughout the atmosphere but depends on factors like temperature, humidity, and air pressure. These variations can create regions of different sound speeds, leading to further bending and curving of the sound wave's path.
As a result of these interactions, the sound wave may take a complex and curved trajectory from the source to your ear, especially in environments with numerous objects or irregularities. However, in certain conditions where there are no obstacles or significant variations in the surrounding environment, the sound wave can propagate more directly and follow a relatively straight path.
It's worth noting that these effects are more pronounced for high-frequency sounds and over longer distances. For low-frequency sounds and short distances, the direct path approximation can be more accurate.