|Definition:|| solution to the inhomogeneous Helmholtz equation|
Note 1 to entry: For a point source at , the inhomogeneous Helmholtz equation is, where ρ is the medium's time-averaged mass density, k is the acoustic wavenumber and is the transfer function, x is the position and f is the acoustic frequency.
Note 2 to entry: For a point source in infinite free space, the transfer function is , where .
Note 3 to entry: Jensen, F. B., Kuperman, W. A., Porter, M. B. and Schmidt, H. Computational Ocean Acoustics, AIP press Springer-Verlag, ISBN: 978- 1-4419-8677-1, 2011. DOI 10.1007/978-1-4419-8678-8. Page 84-85. of Jensen et al. (2011) refers to propagation loss as "transmission loss". Jensen et al. (2011) refers to the transfer function as the "transmission loss pressure".