MEASUREMENT OF NEW ENERGETIC PARAMETERS FOR THE OBJECTIVE CHARACTERIZATION OF AN OPERA HOUSE

Following a rigorous approach to the energetic analysis of sound fields, the measurement of new quantities for the physical description of the behavior of sound in enclosed spaces has been carried out inside an Italian opera house. A first set of measures has been performed during the steady state, allowing the study of the new discovered property calledsound intensity polarization , which accounts for the amount of energy oscillating thorugh the measurement point. Then, in order to accomplish a complete statistical study of the transient field behaviour, the full set of quantities involved in the energy continuity equation (total sound energy density and intensity) has been obtained by means of the extension of the classical Schroederʹs method to the quantities depending also on the air particle velocity solution of the wave equation. Finally, two newly defined field indicators, accounting for the local amount of sound energy radiation and the balance between the potential and kinetic parts of the total sound energy density, have been investigated.