Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements

Insufficient diffuseness is the major cause of the poor repeatability and reproducibility of building acoustical measurements in a reverberation chamber. Inaccurate results were reported for the prevailing methods in ISO and ASTM standards. Many previous studies, thus, have proposed new methods to q...

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Autores principales: Shuying Zhang, Joonhee Lee
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Lenguaje:EN
Publicado: MDPI AG 2021
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Acceso en línea:https://doaj.org/article/67c509e4ebf84b249f91dad88ac7dc3c
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spelling oai:doaj.org-article:67c509e4ebf84b249f91dad88ac7dc3c2021-11-25T16:59:43ZDiffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements10.3390/buildings111105192075-5309https://doaj.org/article/67c509e4ebf84b249f91dad88ac7dc3c2021-11-01T00:00:00Zhttps://www.mdpi.com/2075-5309/11/11/519https://doaj.org/toc/2075-5309Insufficient diffuseness is the major cause of the poor repeatability and reproducibility of building acoustical measurements in a reverberation chamber. Inaccurate results were reported for the prevailing methods in ISO and ASTM standards. Many previous studies, thus, have proposed new methods to quantify the diffuseness of a reverberation chamber more accurately, but there is no general agreement among researchers on the most reliable method. The number of measurement samples required for these diffuseness metrics is also unclear, even though it significantly impacts the robustness of the methods. This study, therefore, aims to compare the performance of the two widely used diffuseness metrics (spatial variation of sound pressure levels and the relative standard deviation of decay rates) in the standards and the recently introduced metric (degree of time series fluctuation). The measurements were carried out with fine resolution microphone positions and varied configurations of acoustic diffusers. The degree of time series fluctuation showed the best correlation with varying diffuser configurations in the low-frequency range. Confidence intervals and coefficients of variation of the three metrics by random sampling also indicated that DTF is more reliable for evaluating the diffuseness in a sound field as it is less influenced by the number of sampling.Shuying ZhangJoonhee LeeMDPI AGarticlereverberation chamberdiffuseness quantificationmeasurement samplingBuilding constructionTH1-9745ENBuildings, Vol 11, Iss 519, p 519 (2021)
institution DOAJ
collection DOAJ
language EN
topic reverberation chamber
diffuseness quantification
measurement sampling
Building construction
TH1-9745
spellingShingle reverberation chamber
diffuseness quantification
measurement sampling
Building construction
TH1-9745
Shuying Zhang
Joonhee Lee
Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements
description Insufficient diffuseness is the major cause of the poor repeatability and reproducibility of building acoustical measurements in a reverberation chamber. Inaccurate results were reported for the prevailing methods in ISO and ASTM standards. Many previous studies, thus, have proposed new methods to quantify the diffuseness of a reverberation chamber more accurately, but there is no general agreement among researchers on the most reliable method. The number of measurement samples required for these diffuseness metrics is also unclear, even though it significantly impacts the robustness of the methods. This study, therefore, aims to compare the performance of the two widely used diffuseness metrics (spatial variation of sound pressure levels and the relative standard deviation of decay rates) in the standards and the recently introduced metric (degree of time series fluctuation). The measurements were carried out with fine resolution microphone positions and varied configurations of acoustic diffusers. The degree of time series fluctuation showed the best correlation with varying diffuser configurations in the low-frequency range. Confidence intervals and coefficients of variation of the three metrics by random sampling also indicated that DTF is more reliable for evaluating the diffuseness in a sound field as it is less influenced by the number of sampling.
format article
author Shuying Zhang
Joonhee Lee
author_facet Shuying Zhang
Joonhee Lee
author_sort Shuying Zhang
title Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements
title_short Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements
title_full Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements
title_fullStr Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements
title_full_unstemmed Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements
title_sort diffuseness quantification in a reverberation chamber and its variation with fine-resolution measurements
publisher MDPI AG
publishDate 2021
url https://doaj.org/article/67c509e4ebf84b249f91dad88ac7dc3c
work_keys_str_mv AT shuyingzhang diffusenessquantificationinareverberationchamberanditsvariationwithfineresolutionmeasurements
AT joonheelee diffusenessquantificationinareverberationchamberanditsvariationwithfineresolutionmeasurements
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