When it comes to the shape that allows sound to travel the farthest, there isn't a specific shape that universally guarantees the longest travel distance for sound. The propagation of sound depends on various factors, including the environment, atmospheric conditions, and the medium through which the sound waves are traveling.
In general, sound waves travel most efficiently through homogeneous mediums, such as air, water, or solids. In open spaces with minimal obstacles, sound waves tend to spread out spherically, radiating in all directions from their source. This spherical spreading causes the sound intensity to decrease with distance as the waves spread out over a larger area.
In certain situations, sound can be focused and directed to travel longer distances through specific shapes or structures that allow for better sound wave propagation. For example, curved surfaces can help reflect and focus sound waves in a particular direction, such as in parabolic reflectors used in satellite dishes or certain architectural designs in concert halls.
However, it's important to note that the distance sound can travel is influenced by numerous factors, including the initial sound intensity, the frequency of the sound waves, and the absorption and scattering properties of the medium through which the sound is propagating.