| Summary: | In urban areas, noise levels can largely vary in space and time due to the great complexity of these environments. The time required for the fluctuations of the running equivalent level <i>L<sub>Aeq</sub></i> to be limited within a preset variability range is a key issue for determining a statistically representative sample of the urban acoustic environment. The goal of the present study is to evaluate the potential of the stabilization time, defined as the minimum time <i>ST</i> after which the difference between the corresponding continuous equivalent sound pressure level <i>L<sub>Aeq,ST</sub></i> and the continuous equivalent sound pressure level <i>L<sub>Aeq,T</sub></i> referred a longer time <i>T</i>, including <i>ST</i>, is never greater than a preset uncertainty interval <i>ε</i>. For this purpose, a dataset of road traffic noise continuously monitored in 97 sites in the city of Milan, Italy, is considered, providing 268 time series of 1 s short <i>L<sub>Aeq,1s</sub></i>, each lasting 24 h. The stabilization time <i>ST</i> referred the hourly <i>L<sub>Aeq,1h</sub></i> was determined for three preset uncertainty intervals <i>ε</i>, namely ±0.5, ±1.0 and ±1.5 dB(A). The results are promising and provide useful hints to obtain short-time noise monitoring as a statistically representative sample of the urban acoustic environment and, therefore, can be a tool to increase the low spatial resolution usually achievable by unattended permanent monitoring units.
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