Please use this identifier to cite or link to this item: http://hdl.handle.net/10216/467
Author(s): António P. O. Carvalho
Victor Desarnaulds
Yves Loerincik
Title: Acoustic behavior of ceramic pots used in middle age worship spaces - a laboratory analysis
Issue Date: 2002
Abstract: This paper presents the theoretical analysis and the results of laboratory measurements of ceramic acoustic pots similar to those used in the vaults and walls of some Middle Age churches in Switzerland and other countries. The resonance frequency of the pots was found to be from 237 Hz to 444 Hz with a high quality factor (average 5.5). A good estimation of the resonance frequency is given by the formula of Alster (with a cylindrical modeling) or by the traditional formula for Helmholtz resonators, slightly adapted. Measurements of the pressure variations inside and outside the pots showed their response in the frequency domain, their natural modes, and also their weak reverberation time (0.13 to 0.48 s), all in accordance with the theory. The intensimetric and sound level measurements highlighted a weak-operating range for the pots (difference open/closed pot on a radius of 0.3 m) of the omnidirectional re-emitted wave by the pots at the natural frequency and at certain harmonics. The sound absorption measurements in reverberation chamber highlighted a small (less than 0.05) but very selective sound absorption. In conclusion, the acoustic pots present, around their resonance frequency and certain harmonics, light phenomena of amplification, sound absorption and diffusion.
Subject: Acústica, Engenharia civil
Acoustics, Civil engineering
Call Number: 55282
URI: http://hdl.handle.net/10216/467
Source: Proceedings of the 9th International Congress on Sound and Vibration
Document Type: Artigo em Livro de Atas de Conferência Internacional
Rights: restrictedAccess
License: https://creativecommons.org/licenses/by-nc/4.0/
Appears in Collections:FEUP - Artigo em Livro de Atas de Conferência Internacional

Files in This Item:
File Description SizeFormat 
55282.pdf134.07 kBAdobe PDF    Request a copy


This item is licensed under a Creative Commons License Creative Commons