Analysis of factors influencing the measurement result of the reverberant sound absorption coefficient under laboratory conditions

• Autorzy: Czapla Marcjanna , Wszołek Tadeusz

Identyfikatory

DOI

10.21008/j.0860-6897.2022.1.03

• Języki publikacji: EN

Abstrakty

EN

There are still discrepancies in the measurement results despite the standardized methods of measuring the sound absorption coefficient in the reverberation room. They appear especially in interlaboratory tests. The research used the method included in the EN-ISO 354: 2003 standard to determine the sound absorption coefficient. The subject of scientific research was to investigate the impact of measurement techniques (Maximum Length Sequence method and interrupted noise method for both T20 and T30 evaluation ranges), humidity in the test room, sample seasoning and sample fitting, and finally the influence of room variability on the measurement results. The tests were performed in two reverberation chambers. The study included two types of materials. Samples (1) made of identical pieces of mineral wool (ISOVER glass wool and ROCKWOOL rock wool) and (2) of fibreboard. Mineral wool was of different thicknesses. Among the measurement techniques, the smallest dispersion of the reverberation time results was obtained with the MLS -T30 method, and the highest differences in the results were caused by the test being performed in another room (reverberation chamber). There was no significant influence with the increase in humidity or the careful arrangement of the test sample from the components on the measurement result.

Słowa kluczowe

EN

sound absorption coefficient; reverberation room; reverberation time; MLS method

PL

współczynnik pochłaniania dźwięków; komora pogłosowa; czas pogłosu; metoda MLS

• Wydawca: Poznan University of Technology. Institute of Applied Mechanics
• Czasopismo: Vibrations in Physical Systems
• Rocznik: 2022
• Tom: Vol. 33, nr 1
• Strony: art. no. 2022103
• Opis fizyczny: Bibliogr. 12 poz., fot. kolor., 1 rys., wykr.

Twórcy

autor

Czapla Marcjanna

• AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Department of Mechanics and Vibroacoustics, Al. Mickiewicza 30, 30-059 Kraków, Poland

• https://orcid.org/0000-0003-2914-7666

autor

Wszołek Tadeusz

• Wszołek, Tadeusz

• https://orcid.org/0000-0001-5057-3227

Bibliografia

• 1. ISO 354:2003. Acoustics- Measurement of sound absorption in a reverberation room.
• 2. W. Bartnik, G. Wszołek; Influence of the measured quantities on the repeatibility, reproductibility and accuracy in measurements of the reverberation sound absorption coefficient (in polish: Wpływ mierzonych wielkości na powtarzalność, odtwarzalność oraz dokładność pomiaru pogłosowego współczynnika pochłaniania dźwięku); XX Conference on Acoustic and Biomedical Engineering, Kraków - Zakopane, 15-19 April, 2013, 152-156.
• 3. C. Scrosati et al.; Towards more reliable measurement of sound absorption coefficient in reverberation rooms: An Inter-Laboratory Test; Appl. Acoustics, 2020, 165, 49-53. DOI:10.1016/j.apacoust.2020.107298.
• 4. A. Iżewska, T. Czyżewski; Uncertainty of measurement of sound absorption coefficient in reverberation room (in polish: Niepewność pomiaru współczynnika pochłaniania dźwięku w komorze pogłosowej); Prace Instytutu Techniki Budowlanej, 2011, 1, 157, 3-13.
• 5. M. Vercammen; On the revision of ISO 354, measurement of the sound absorption in the reverberation room; Proceedings of the 23rd International Congress on Acoustics, Aachen, Germany, 9-13 Sep. 2019, 3991-3997.
• 6. A. Cops, J. Vanhaecht, K. Leppens; Sound absorption in a reverberation room: causes of discrepancies on measurement results, Appl. Acoustics, 1996, 46(3), 215-232. DOI:10.1016/0003-682X (95)00029-9.
• 7. A.C.C. Warnock; Some practical aspects of absorption measurements in reverberation rooms; J. Acoust. S. Am., 1983, 74(5) ,1422-1432. DOI:10.1121/1.390144.
• 8. F. V. Hundt; The absorption coefficient problem; J. Acoust. S. Am., 1939, 11, 38-40. DOI: 10.1121/1.1916003.
• 9. D. Mleczko, T. Wszołek; Effect of diffusing elements in a reverberation room on the results of airborne sound insulation laboratory measurements; Arch. Acoustics, 2019, 44(4), 739-746. DOI: 10.24425/aoa.2019.129729.
• 10. ISO 9613-1:1999, Acoustics ― Attenuation of sound during propagation outdoors ― part 1: Calculation of the absorption of sound by the atmosphere.
• 11. M. Czapla; Analysis and evaluation of sources of uncertainty in experimental studies of the sound absorption coefficient (in polish: Analiza i ocena źródeł niepewności w badaniach doświadczalnych pogłosowego współczynnika pochłaniania dźwięku), Praca magisterska AGH, Kraków, 2020.
• 12. EN ISO 11654:1997, Acoustics - Sound absorbers for use in buildings - Rating of sound absorption.

Uwagi

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023).