Inter Laboratory Comparison of Environmental Noise Measurement

Results of an inter laboratory comparison for environmental noise measurements are presented in this article. 18 laboratories took part in this study. A purpose of individual measurement was to quantify environmental noise levels, calculate noise descriptors and compare them with community noise regulations. Measurements and calculations were performed according to standards ISO 1996-1:2005, ISO 1996-2:2007 and national legislation. A loudspeaker was used as a reference noise source. It was mounted at the top of the hayloft just below the roof. The loudspeaker emitted a pink noise, representing a constant broadband noise source. The noise source was operating from 8:00 in the morning to 16:00 at the afternoon, each day for 4 weeks. During this time, laboratories performed all required measurements. Each laboratory performed measurements independently from other laboratories and according to its own procedures. Measurement results of equivalent noise level L _Aeq, percentile values L ₁, and calculation of noise descriptors L _d and L _den were compared. An estimation of measurement uncertainty for a given environmental conditions and measurement setup conditions is given.