What is the dB loss associated with dipolar spreading?

Dipolar spreading is a type of sound propagation that occurs in a medium where the sound energy radiates away from the source in a pattern that resembles two opposing lobes or dipoles. This dispersion of energy into a three-dimensional space results in a decrease in sound intensity as the distance from the source increases.

In the case of dipolar sources, the sound intensity decreases with the square of the distance from the source, leading to a specific amount of decibel (dB) loss. For dipolar sound fields, the typical loss is calculated as 12 dB per doubling of distance. This is due to the unique geometry of dipolar spreading, which contrasts with spherical spreading that typically results in a 6 dB loss per doubling of distance.

Understanding the principles of sound propagation and loss in various spreading patterns is essential for analyzing underwater acoustics, particularly in naval or oceanographic environments. The 12 dB loss indicates that the energy from a dipolar source diminishes significantly more than what would occur in simpler spreading conditions, highlighting the complex behavior of sound in deeper media.