The draft international standard method (ISO/DIS 9613-2) for calculating the attenuation of sound during propagation outdoors

The International Standards Organization (ISO) technical committee TC 43 on Acoustics, sub-committee SC1 on Noise, in 1983 voted to form a new working group, WG24, with the objective `to specify methods for determining the attenuation of sound propagating outdoors. This information is necessary for determining sound pressure levels at a distance from a noise source, e.g. an industrial plant, a vehicle or an aircraft'. This objective placed the project squarely between two sets of existing ISO standards-those specifying methods for determining the levels of sound power emitted by various sources, such as machinery and specified equipment (the ISO 3740 series) or industrial plants (ISO 8297), and the ISO 1996 series which specifies methods for the description of noise outdoors in community environments