Characterization of quiet areas: Subjective evaluation and sound‐level indices

In densely populated regions, a government may decide to conserve quiet areas within reach of the average population. To characterize such areas, long‐term exposure measures and typical limits have to be decided upon. Since the main goal of the silent area is to provide repose for Man, a subjective evaluation of silence may also be envisaged. In this paper, subjective evaluation of silence and sound‐level measurements obtained in two related, but independent studies of open area are compared. Thorough statistical analyses lead to the conclusion that statistical noise levels with larger index (LA95 to LA50) are best suited to predict subjective silence. Critical levels are obtained. They lead to over 80% correct classification for both studies. Reported disturbance, on the other hand, seems correlated to events, but does not have a strong influence on the global rating of silence.