No, sound does not always travel in a perfectly straight line. The propagation of sound waves depends on various factors such as the medium through which the sound travels, the presence of obstacles or barriers, and the environmental conditions.
In a homogeneous medium with a uniform temperature and pressure, sound waves generally propagate in straight lines. This is often observed in ideal conditions where there are no obstacles or significant changes in the medium.
However, in real-world scenarios, sound waves can be influenced by several factors. For example, when sound encounters obstacles such as walls, buildings, or other objects, it can diffract, reflect, or refract. Diffraction refers to the bending of sound waves around obstacles, while reflection occurs when sound waves bounce off surfaces, and refraction happens when sound waves change direction as they pass through different mediums.
Moreover, environmental conditions like temperature and wind can affect the path of sound. Temperature inversions, where there are layers of air with different temperatures, can cause sound to refract and travel along curved paths.
In summary, while sound generally travels in straight lines in ideal conditions, it can be influenced and deviate from a straight path when encountering obstacles or variations in the medium or environmental conditions.