Focused Study on the Quiet Side Effect in Dwellings Highly Exposed to Road Traffic Noise

This study provides additional evidence for the positive effect of the presence of a quiet facade at a dwelling and aims at unraveling potential mechanisms. Locations with dominant road traffic noise and high L-den-levels at the most exposed facade were selected. Dwellings both with and without a quiet facade were deliberately sought out. Face-to-face questionnaires (N = 100) were taken to study the influence of the presence of a quiet side in relation to noise annoyance and sleep disturbance. As a direct effect, the absence of a quiet facade in the dwelling (approached as a front-back facade noise level difference smaller than 10 dBA) leads to an important increase of at least moderately annoyed people (odds-ratio adjusted for noise sensitivity equals 3.3). In an indirect way, a bedroom located at the quiet side leads to an even stronger reduction of the self-reported noise annoyance (odds-ratio equal to 10.6 when adjusted for noise sensitivity and front facade L-den). The quiet side effect seems to be especially applicable for noise sensitive persons. A bedroom located at the quiet side also reduces noise-induced sleep disturbances. On a loud side, bedroom windows are more often closed, however, conflicting with the preference of dwellers.