Division: Long-term sound level at point R for all paths - Commission Directive (EU) 2015/996 of 19 May 2015 establishing common noise assessment methods according to Directive 2002/49/EC of the European Parliament and of the Council (Text with EEA relevance)

The total long-term sound level at the receiver for a frequency band is obtained by energy summing contributions from all N paths, all types included:

L_{tot,LT} = 10 \times \lg (\sum_{n} 10^{\frac{L_{n,LT}}{10}})

(2.5.10)

where

n is the index of the paths between S and R.

Taking reflections into account by means of image sources is described further. The percentage of occurrences of favourable conditions in the case of a path reflected on a vertical obstacle is taken to be identical to the occurrence of the direct path.

If S′ is the image source of S, then the occurrence p′ of the path (S′,R) is taken to be equal to the occurrence p of the path (S_i,R).

Division Long-term sound level at point R for all paths