Predicting energy-based acoustic parameters in churches: an attempt to generalize the μ-model

The paper describes the application of an energy model, already tested on Spanish churches, to a different and larger group. Its simplicity allows fast prediction of every energy parameter, provided that its corrective parameter μ is known. The results of an acoustic survey carried out in more than thirty Italian churches are used in order to try to generalize the model. Different values of the μ- parameter are calculated by means of a semiempirical prediction of clarity. The study investigates in greater detail how the acoustic energy varies inside the churches. In fact, chapels, columns, trussed roofs or vaults scatter the reflections, resulting in weaker early reflections as the complexity of the church grows. The reduction observed is greater in large Italian churches than in small Mudejar- Gothic churches in Seville, showing the need to classify different values of the μ-parameter. Predicted values of some energy parameters calculated according to μ values show good agreement with experimental data. The proposed classification suggests a wider use of the model for churches of different typologies.