A proposed international standard method for calculating the attenuation of sound during propagation outdoors

This method aims to predict noise levels in the community, with engineering precision, from a variety of sources (ideally any source) of known sound power. It represents an integration by the members of working group ISO/TC43/SC1/WG24 of the national methods, principally from The Netherlands, the Scandinavian countries, Germany, and the USA. This method aims to determine the average sound level LAeq.T under meteorological conditions favorable to propagation (a worst case scenario), and then obtain from that a long‐term average sound level LAeq.LT, both as specified in ISO 1996. It consists specifically of octave band algorithms (with center frequencies from 63–8000 Hz) for calculating the attenuation of sound from a point source., or an assembly of point sources.