Compute the loudness of a point source at a certain distance, based upon a measurement at a different distance.

The theory of this numerical example is described at www.natuurkunde.nl, in dutch. The theory describes exponential dissipation of sound with distance and decay with distance according to the inverse square law. The theory does not take into account the effect of the soil, barriers, reflections, wind, and atmospheric effects.

By adding the loudnesses of multiple point sources you can model more complex sources of sound. Adding the loudnesses of sound sources can be done with this calculator. For instance three point sources on a line form an elementary sound model for a road.

See also this calculator dealing with traffic noise.

This example takes both the inverse square law for distance and exponential damping of sound over large distances into account with a rate of 10^{-0,0003 r}, where r is the distance to the source. The damping factor (0.0003) increases with frequency so you can adjust it in your computations.