Which type of sound spreading has the lowest loss and the greatest detection range?

Cylindrical spreading is characterized by sound waves propagating outward from a source in such a way that the energy is distributed evenly over a cylindrical surface. This type of spreading results in a gradual decrease in intensity over distance, but not as steeply as spherical spreading. In cylindrical spreading, the sound wave retains more of its energy over large distances compared to other spreading types, allowing for lower loss of signal strength as it travels through the medium.

The geometry of cylindrical propagation allows the sound energy to remain concentrated in a specific cylindrical region, making it more effective for long-distance detection. This leads to a greater detection range, which is particularly advantageous in oceanographic applications where detecting distant sounds is crucial, such as submarine communication or marine life monitoring.

In contrast, spherical spreading causes the sound energy to dilute over the surface area of a growing sphere, leading to greater losses at distance. Planar spreading suggests a flat wavefront that, while useful in specific contexts, can also lead to increased attenuation due to environmental factors. The term "attenuated" typically describes sound that has already experienced significant loss, which does not align with the goal of maximizing detection range. Therefore, cylindrical spreading stands out as the optimal choice for achieving lower loss and longer detection distances.