Room acoustic modelling of textile materials hung freely in space: from the reverberation chamber to ancient churches

Abstract

The aim of this study is to investigate how sound absorbing materials like curtains should be modelled in geometrical acoustic (GA) software when hung freely in space. The use of these tools is widespread today. Whatever the scope of the simulation, dealing with textile materials can be particularly challenging as they both absorb and transmit sound, and absorption is dependent on distance of the walls. Therefore, care must be taken to enter properly validated data. Absorption coefficients found in the literature are measured with samples close to wall, and are not suitable when materials are hung freely. The effects of material placement on both absorption and transmission coefficients were therefore investigated using scaled-down physical models of a reverberant chamber and a church. Subsequently, GA models of both spaces were used to demonstrate that simulated results are reliable assuming that absorption and transmission coefficients are correctly determined.

Keywords:

• acoustic simulation
• sound absorption
• textile materials
• church acoustics

Acknowledgments

The authors are finally grateful to the anonymous reviewers for their constructive criticism and suggestions for the improvement of the manuscript.

ORCID

F. Martellotta http://orcid.org/0000-0002-0057-2194

A. Alonso http://orcid.org/0000-0002-0321-1730

Additional information

Funding

This work has been partially funded by the Spanish Ministry of Science and Innovation and FEDER funds, with references PatrimoniUN10 CEI 2014/731 and BIA2014-56755-P. One of the authors (A. Alonso) received an FPU grant from the Spanish Government (ref. FPU12/04949).