Noise screening effects of balconies on a building facade.

The insertion loss and its spectrum due to a rectangular balcony on a building facade in the presence of sound reflection and scattering from adjacent balconies were examined using a scale model. The front panel of the balcony dictates the screening performance, while the side walls of the balcony are found to be insignificant. Balconies without a front panel do not provide acoustic protection in the presence of upper balcony reflection, especially for a distant noise source. Sound amplifications are also observed in many cases. In addition, the shapes of the insertion loss spectra are found to depend on the elevation angle of the balcony. Significant correlations between the A-weighted balcony insertion losses with this angle are found in the absence of upper balcony reflections. With such reflection, an angle defined using the balcony configuration and source position correlates within engineering tolerance to the insertion losses.