Estimation of the long term average sound level from hourly average sound levels

It is shown how to estimate the long-term average sound level, LAeqLT (for free flowing road traffic) from measurements of the hourly A-weighted equivalent sound level, LAeq1h. To estimate the parameters of the model which describe noise emission and attenuation, concurrent measurements of LAeq1h at two distances from the considered road are needed. A semi-empirical formula is derived for LAeqLT approximation. Also the uncertainty of this approximation is given as a function the distance from the road and receiver height.