Representative monitoring of environmental noise levels for BS4142:2014

Abstract

The aim of this paper is to illustrate best practice in the monitoring of environmental noise levels from industrial sources as determined by the Environment Agency. BS4142:2014 makes regular mention of the requirement for 'representative monitoring'. This requirement is also mentioned in BS7445-1:2003 and BS7445-2:1991, and the IoA-IEMA "Guidelines for Noise Impact Assessment". Nevertheless, the requirement for representative monitoring is commonly overlooked by practitioners during environmental noise impact assessments. This paper will present noise monitoring examples from different industries. The data will be interpreted using modal analysis of discrete short periods and rolling hourly periods. The results of these different forms of analysis demonstrate whether a short or an hourly period can be considered representative of a longer monitoring period. It is concluded that for the industrial sources considered, monitoring periods exceeding an hour are required to sufficiently minimize the uncertainty to more than 50% of the data within ±1dBA.