The acoustical influence of balcony depth and parapet form: experiments and simulations

The influence of balcony depth and parapet form on the acoustical performance of building facades close to roadways have been investigated. Various depths and two inclinations of parapet have been modeled on an eight floor building. Pyramid ray-tracing simulations and scale model measurements have been carried out. The predicted and measured A-weighted sound pressure level reductions over the balcony back wall and in free field conditions have been compared. The results have been used to derive empirical equations for predicting protection as a function of geometrical parameters. The protection obtained by various parapet depths ranges between 4 and 8 dB(A), while an additional protection of between 0.5 and 4 dB(A) can be obtained by inclining the parapets.