Application of Gauss' Law in Acoustics
  Practical application of Gauss' law in acoustics is not a very well known method. However, any inverse square law behavior can be formulated in the way similar to Gauss' law, which allows us to extend the same principle to sound waves propagation. We show in this paper how the acoustic power of sound source can be related to the sound intensity flow through a given surface by means of the Gauss' law. Several different sound-source shapes, important in practical applications, are analyzed by means of the Gauss' law. A suitable choice of the Gaussian surface allows us to obtain the simple and straightforward method for calculating the sound intensity distribution in space. 
Mladen Martinis and Zoran Ozimec
physics.flu-dyn