Measurement time of urban noise in Montevideo (Uruguay) and Medellin (Colombia).

Abstract

The duration of ambient noise measurements is one of the susceptible aspects regarding the correct design of a large measurement campaign, for example, to build an urban acoustic map. Previous work in Montevideo and Medellin lead to determine the stabilization time of the measurements with the aim of achieving accuracies from ± 1 to ± 3 dB in relation to the value of Leq,1h and Leq,d (Leq of the daytime). Montevideo data were taken at five points of the city, with traffic densities (IMH, time average intensity) from 200 to 1700 vph. Medellin data were taken in two monitoring stations, each equipped with a fixed sound level meter. In one of the stations, the IMH value is 1880 vph, while in the other one is 2120 vph except Sundays, when it is reduced to approximately 950 vph. Measured LA,eq,1h and Leq,d values are compared with those obtained for the same period with data corresponding to samples of 10, 15, 20, and 30 min. In both cases, the representativeness of the measurements increases with the enlargement of measurement time. Despite their great differences, both cities admit similar durations for measurements of urban noise to obtain representative data.