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1

Influence of paint coatings on the sound absorption coefficient

Żyłka Wojciech Marek, Świrk Patrycja, Pater Marcin Adam, Leniowska Lucyna

Advances in Science and Technology. Research Journal

|

2026

|

Vol. 20, no. 5

130--142

EN

Paint coatings are commonly used to protect industrial components, but their influence on acoustic behaviour is still not fully understood. The aim of this study is to quantify how the type of paint and the number of coating layers affect the sound absorption of metal, expanded polystyrene (EPS), and extruded polystyrene (XPS) samples. Normal-incidence sound absorption coefficients were measured in an impedance tube over the 100–5700 Hz frequency range for uncoated samples and for samples coated with ceramic paint and water-based acrylic lacquer in one- and two-layer configurations. For metal substrates, applying two layers of ceramic paint resulted in the main resonance being observed to move from about 3.8 kHz to around 3.0 kHz and reduced the peak absorption coefficient from ~0.87 to ~0.60, indicating a clear mass-induced tuning of the resonance frequency. In XPS and EPS samples, coatings generally broadened and flattened the absorption curves while slightly reducing the maximum absorption. For XPS, results were averaged over 17 samples to reduce the effect of material heterogeneity, and measurement uncertainty was evaluated according to ISO 10534-2. Microscopic observations confirmed that the coatings smooth the surface and partially close open pores; combined with the increased surface mass, this modifies the resonance behaviour of the samples. The results demonstrate that paint coatings can influence the resonance frequency and bandwidth of sound absorption in lightweight structures, which may be exploited in future studies on the passive acoustic tuning of materials. The work is limited to normal-incidence tube measurements and does not include direct thickness measurements or detailed resonance modelling, which will be addressed in further research.

2

The influence of diffuser configuration in a reverberation room on sound absorption coefficient measurements

Mleczko Dominik

Materiały Budowlane

|

2025

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nr 8

213--219

EN

The aim of the study was to evaluate the impact of diffuser arrangement in a reverberation room on the values of the sound absorption coefficient determined from reverberation time measurements in accordance with ISO 354. Measurements were carried out for four configurations, both with and without a sound‑absorbing sample. The results showed that the diffuser layout can affect the outcomes, particularly at low frequencies, confirming the sensitivity of the measurements to acoustic field conditions.

PL

W artykule zaprezentowano ocenę wpływu rozmieszczenia rozpraszaczy w komorze pogłosowej na wartość współczynnika pochłaniania dźwięku wyznaczanego na podstawie czasu pogłosu zgodnie z ISO 354. Badania wykonano w czterech konfiguracjach, z materiałem pochłaniającym i bez. Wykazano, że układ rozpraszaczy może wpływać na uzyskiwane wyniki, szczególnie w zakresie niskich częstotliwości, co potwierdza wrażliwość pomiarów na warunki pola akustycznego.

3

Study of sound‑absorbing and insulating properties of regenerable materials to reduce noise

Świrk Patrycja, Leniowska Lucyna

Materiały Budowlane

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2025

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nr 8

166--172

EN

Many available sound‑absorbing materials are made from reticulated foam, fibrous, granular, or loose materials compressed together, for example, under the influence of temperature, while maintaining a porous structure. However, most of them quickly degrade under the influence of environmental conditions, temperature, humidity, etc. In this work, an acoustic metamaterial is proposed that can be used as an absorber to obtain broadband sound absorption for acoustic silencers that reduce noise emitted during the discharge of gases or the process of air. The absorbers are installed inside the acoustic silencers, where they are exposed to the turbulent flow of a potentially contaminated or viscous fluid with suspended dust particles and carried along with the flow. The aim of the research is to develop materials that are characterised by good absorption properties and that also exhibit high resistance to moisture. Several samples of granulated materials, with regular shapes and different sizes of granules were selected for the study. It was found that high humidity does not affect the acoustic properties of the considered samples and it does not cause negative changes in the material structure. The proposed material consisting of plastic granules of different diameters is resistant to moisture and can be easily regenerated in the case of severe contamination.

PL

Wiele dostępnych materiałów dźwiękochłonnych jest wykonanych z pianki o strukturze siatkowanej, włóknistej, granulowanej lub luźnej, sprasowanej razem, np. pod wpływem temperatury. W wyniku tego powstaje struktura porowata. Ulega ona jednak szybko degradacji pod wpływem warunków środowiskowych, temperatury, wilgotności itp. W artykule zaprezentowano metamateriał akustyczny, który może być stosowany jako absorber szerokopasmowego pochłaniania dźwięku w przypadku tłumików akustycznych, które redukują hałas emitowany podczas odprowadzania gazów. Absorbery są instalowane wewnątrz tłumików akustycznych. Są tam narażone na turbulentny przepływ potencjalnie zanieczyszczonego lub lepkiego płynu z zawieszonymi cząstkami pyłu i przenoszone wraz z jego przepływem. Celem przeprowadzonych badań było opracowanie materiałów charakteryzujących się dobrymi właściwościami absorpcyjnymi, a także wykazujących dużą odporność na wilgoć. Do badań wybrano kilka próbek materiałów granulopodobnych o regularnych kształtach i różnej wielkości granulek. Stwierdzono, że duża wilgotność nie wpływa na właściwości akustyczne ocenianych próbek i nie powoduje negatywnych zmian w ich strukturze. Proponowany materiał składający się z granulek tworzywa sztucznego o różnej średnicy jest odporny na wilgoć i może być łatwo regenerowany w przypadku znacznego zanieczyszczenia.

4

Mobile and stationary methods for measuring and assessing of noisiness of road pavements

Gardziejczyk Władysław, Motylewicz Marek

Materiały Budowlane

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2025

|

nr 8

81--88

EN

The type and kind of road surfaces and their technical condition have a significant impact on the tyre/road noise of motor vehicles. The paper presents possibilities and examples of the use of stationary and mobile methods for measuring and assessing the acoustic properties of pavements for three cases involving the laboratory mix design and road use stages. The results of the example studies confirmed the effectiveness of these methods in assessing the noise performance of road pavements.

PL

Typ i rodzaj nawierzchni drogowych oraz ich stan techniczny mają istotny wpływ na poziom hałasu toczenia pojazdów samochodowych. W artykule przedstawiono możliwości i przykłady wykorzystania stacjonarnych i mobilnych metod pomiaru i oceny właściwości akustycznych nawierzchni w odniesieniu do trzech przypadków obejmujących etapy projektowania mieszanek w laboratorium oraz użytkowania drogi. Wyniki przykładowych badań potwierdziły skuteczność tych metod w ocenie hałaśliwości nawierzchni drogowych.

5

Application of perforated hollow blocks as sound-absorbing structures in the acoustic design of Polish Television film studios

Ziarko Bartłomiej, Łukaszewski Łukasz, Kłosak Andrzej

Materiały Budowlane

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2025

|

nr 12

8--17

EN

The article presents the concept and results of using hollow blocks as sound-absorbing elements in the acoustic design of the interiors of the newly constructed Polish Television film studios in Warsaw. Due to budget constraints and the need to employ simple, durable, and widely available building materials, hollow blocks were adapted as an alternative to conventional acoustic treatments. The paper discusses the integration of these elements with the interior architecture, their geometric parameters, and their influence on the reverberation time within the room. It also presents the results of reverberation time measurements and sound absorption coefficient analyses, which confirmed the effectiveness of the proposed solution. The use of hollow blocks made it possible to achieve favourable acoustic conditions inside film studios while maintaining low construction costs and simplicity of implementation.

PL

W artykule przedstawiono koncepcję oraz wyniki zastosowania pustaków otworowych jako elementów dźwiękochłonnych w projekcie akustyki wnętrz nowo powstałych studiów zdjęciowych Telewizji Polskiej w Warszawie. Ze względu na ograniczenia budżetowe oraz konieczność wykorzystania prostych, trwałych i ogólnodostępnych materiałów budowlanych, pustaki otworowe zostały zaadaptowane jako alternatywa konwencjonalnych ustrojów akustycznych. Omówiono sposób integracji tych elementów z architekturą wnętrza, ich parametry geometryczne oraz wpływ na czas pogłosu w pomieszczeniu. Przedstawiono również wyniki pomiarów czasu pogłosu oraz analizy współczynnika pochłaniania dźwięku, które potwierdziły skuteczność zaprojektowanego rozwiązania. Zastosowanie pustaków otworowych umożliwiło uzyskanie korzystnych warunków akustycznych w halach zdjęciowych z zachowaniem niskich kosztów realizacji i prostoty wykonania.

6

Modeling of the Acoustic Properties of Foamed Polypropylene Panels

Świrk Patrycja, Leniowska Lucyna

Engineering Transactions

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2025

|

Vol. 73, iss. 1

89--101

EN

This article presents research on modelling baffles with the desired properties of the sound absorption coefficient (SAC). The purpose of the study was to model and compare the SAC values based on selected theoretical models with the results obtained from measurements of this coefficient in panels made of foamed polypropylene. The assessment of sound absorption properties was carried out using two theoretical models: the Johnson–Champoux–Allard (JCA) model and the Sgard model. The accuracy of the calculated SAC was verified based on laboratory measurements of this parameter for selected material configurations, using the technique of two microphones in an impedance tube. Both theoretical and experimental studies were conducted on porous materials in the form of granules. The application of the Sgard model yielded the best results, with the smallest discrepancies in relation to the experimental tests. The results can be used to improve the SAC and efficiency of acoustic panels whose basic material is foamed polypropylene.

7

Sensitivity Analysis of Acoustic Parameters in a Theatre Hall : A Case Study of the Maria Zankovetska Theatre in Lviv

Rubacha Jarosław, Pilch Adam, Kinasz Roman, Binek Wojciech, Kamisiński Tadeusz, Melnyk Mykhaylo

Archives of Acoustics

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2025

|

Vol. 50, nr 3

307--320

EN

This article explores the potential for modifying acoustic parameters within a theatre hall, using the Maria Zankovetska Theatre in Lviv, as a case study. The study used sensitivity analysis to evaluate how changes in the sound absorption of specific surfaces affect selected acoustic parameters in the horseshoe-shaped theatre hall. A numerical model of the hall is developed and calibrated based on in-situ acoustic measurements to assess the sensitivity of parameters such as reverberation time (T20), early decay time (EDT), clarity (C50), and early sound strength (G80). The analysis reveals that surfaces such as the stage tower ceiling, stage walls with curtains, audience walls, and seating have the most significant impact on the acoustic parameters. Modifying the sound absorption of these surfaces can affect T20, EDT, C50, and G80. Notably, increasing the absorption of a single surface might not significantly alter C50 and G80 values, whereas reducing the absorption of surfaces such as seating can lead to noticeable changes in these parameters. These findings provide valuable insights for future renovations and acoustic adjustments, aiming to optimize the theatre’s acoustic performance while preserving its historical character.

8

Comparison of Methods for Determining the Airflow Resistivity of Porous and Covering Materials

Melnyk Mykhaylo, Rubacha Jarosław, Flach Artur, Chojak Aleksandra, Kamisiński Tadeusz, Zabierowski Wojciech, Iwaniec Marek, Kernytskyy Andryi

Archives of Acoustics

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2025

|

Vol. 50, nr 4

421--433

EN

This article compares two methods for determining the airflow resistivity of porous and coating materials – a key parameter in sound absorption modelling. The analysis involves a modified static airflow measurement procedure in accordance with International Organization for Standardization [ISO] (2018), using a linear approximation algorithm (PLA), and a reverse method consisting of matching the measured absorption coefficient in an impedance tube to the Miki model. The analysis was conducted on both porous materials utilised in acoustic panel fillings and thin coverings. It is evident that both methods yield analogous outcomes for materials exhibiting low resistivity. However, for materials characterised by higher resistivity, discrepancies of up to 50 % were observed. Nevertheless, a high degree of agreement was obtained between the calculated and measured absorption coefficients. For thin coating materials, an air gap of at least 70 mm is required. For materials with a thickness of up to approximately 30 mm, differences in resistivity do not significantly affect the absorption coefficient. It is evident that both methods can be used to determine the airflow resistivity of porous materials and layered structures, supporting the effective selection of materials according to requirements.

9

Acoustic properties of biodegradable materials in the low and medium frequency range

Świrk Patrycja, Leniowska Lucyna, Korzyńska Katarzyna

Vibrations in Physical Systems

|

2024

|

Vol. 35, nr 2

art. no. 2024208

EN

Materials commonly used in various public spaces are characterized by sound-absorbing or insulating properties. Natural fiber composites are an eco-friendly promising alternative to conventional synthetic fiber composites. For specialized rooms, it is essential to provide good insulation and properly selected sound-absorbing materials. This article presents the results of tests on the acoustic properties of selected natural, biodegradable materials. The aim of the research was to find biodegradable composites that would have good insulating and absorption properties in the low- and medium-frequency ranges. Firstly we tested several configurations of composites made of various wood-based materials in terms of sound pressure vs. frequency. Then, the sound absorption coefficients of the best natural fiber composites used were measured by the technique of two microphone transfer functions in the impedance tube. It was concluded that multi-functional composite materials can be made by natural fibers so that both the good acoustic insulation together with appropriately high sound absorption coefficients in the low and medium frequency range can be achieved.

10

Ocena właściwości akustycznych warstwy ścieralnej z asfaltu porowatego nawierzchni drogowych w warunkach laboratoryjnych

Gardziejczyk Władysław, Motylewicz Marek, Sakowski Mariusz

Materiały Budowlane

|

2024

|

nr 6

32--35

PL

Zastosowanie asfaltu porowatego w warstwie ścieralnej nawierzchni drogowej istotnie wpływa na obniżenie poziomu hałasu opona/nawierzchnia. Parametrami charakteryzującymi właściwości akustyczne warstwy ścieralnej są współczynnik pochłaniania dźwięku i wodoprzepuszczalność. W artykule przedstawiono analizę wyników badań współczynnika pochłaniania dźwięku oraz wodoprzepuszczalności mieszanek z asfaltu porowatego. Stwierdzono istotny wpływ zawartości wolnych przestrzeni w mieszance na wartości badanych parametrów.

EN

The use of porous asphalt in the wearing course of a road pavement has a significant effect on reducing tyre/road noise levels. The parameters characterising the acoustic properties of the wearing course are sound absorption coefficient and water permeability. This paper presents an analysis of the results of a study of the sound absorption coefficient and water permeability of porous asphalt mixtures. A significant influence of the air voids content of the mixture on the values of the parameters studied was found.

11

Designing of sound - absorbing seats for Jastrzebie-Zdroj concert hall

Kłosak Andrzej, Szeląg Agata

Materiały Budowlane

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2024

|

nr 8

69--78

EN

This paper discusses the design, realization and acoustical performance of a sound-absorbing auditorium chairs intended for a concert hall with 350 seats, opened in 2022 at the Music School in Jastrzębie-Zdrój. Several construction aspects were covered: the selection of foam for the seat and upholstery fabric based on measurements of air flow resistance, as well as the influence of the fabric lamination process on the acoustic properties of the seats. The construction of the chair and the acoustic parameters of the completed seats installed in the auditorium were also described. Finally, the article described how we managed to measure the absorption coefficient of occupied seats within the constraints of human contact related to the COVID-19 pandemic.

PL

W artykule omówiono projekt, realizację oraz parametry akustyczne dźwiękochłonnych foteli audytoryjnych przeznaczonych do sali koncertowej na 350 miejsc, otwartej w 2022 r. w Szkole Muzycznej w Jastrzębiu-Zdroju. Omówiono kilka aspektów konstrukcyjnych: dobór pianki tapicerskiej i tkaniny obiciowej na podstawie pomiarów oporu przepływu powietrza, a także wpływ procesu laminowania tkaniny na właściwości akustyczne siedzisk. Opisano również konstrukcję fotela, parametry akustyczne gotowych foteli zainstalowanych w sali oraz sposób, w jaki udało się zmierzyć współczynnik pochłaniania zajętych miejsc w ramach ograniczeń, dotyczących kontaktu międzyludzkiego, związanych z pandemią COVID-19.

12

Modelling the Acoustic Properties of Baffles Made of Porous and Fibrous Materials

Kosała Krzysztof

Archives of Acoustics

|

2024

|

Vol. 49, nr 3

345--357

EN

The research described in the article addresses the problem of measurement, prediction and practical use of the acoustic properties of materials determined in an impedance tube. The aim of the research was to develop a simple calculation model for the insertion loss of small machinery enclosures, based on the normal incidence sound transmission loss and the normal incidence sound absorption coefficient of porous and fibrous materials. Both experimental and model tests were carried out on materials such as mineral wool, melamine foam and rebonded polyurethane foam. Assessing the absorption properties of the tested porous and fibrous materials was performed using selected theoretical models, relating the calculations of the normal incidence sound absorption coefficient to measurements of this parameter conducted using an impedance tube. The application of the modified Allard and Champoux model brought the best results with the smallest discrepancies of the obtained results in relation to the experimental tests. Assessing the sound-insulating properties of the tested mineral wool was carried out using the proposed calculation model for the normal incidence sound transmission loss, relating the obtained results to measurements conducted using an impedance tube. The assessment of the sound-insulating properties of porous and fibrous materials was performed using the proposed calculation model for insertion loss, which was validated using two prototype test stands for determining the insertion loss of cubic enclosures, in this case with walls made of porous and fibrous materials. Satisfactory results were obtained for engineering applications in the calculation results using the proposed models with respect to measurements. The results may have practical applications in assessing the effectiveness of acoustic enclosures, in which the basic construction material is an appropriate porous or fibrous plate, selected to have both sound-absorbing and sound-insulating properties.

13

The use of sound-absorbing properties of acoustic panels with different degree of perforation on the outer lining layer in modeling and calculations of traffic noise

Żuchowski Rafał, Nowoświat Artur, Pudełko Bartłomiej, Dulak Leszek

Vibrations in Physical Systems

|

2023

|

Vol. 34, nr 2

art. no. 2023219

EN

The article presents research studies on the impact of perforation of the outer lining layer of an acoustic panel used for the construction of road noise reduction devices on its absorbing properties. The research included measurements of the reverberation time in the laboratory conditions of diffusion field, on the basis of which the values of sound absorption coefficient as a function of frequency were determined. In addition, for various solutions of acoustic panels based on a corrugated fiber cement board on the top surface and on two types of mineral wool inside the panel, the αw and αp indices as well as sound absorption rating index DLαNRD were calculated. Then, computer simulations were carried out to show the influence of laboratory-determined acoustic parameters of the panels on the acoustic climate in the vicinity of a selected transport system. The key aspects of the modeling process are presented, the characteristics of the noise source and the analysis of the results are described. An important goal of traffic noise modeling is to strive to develop more friendly and sustainable material solutions that will reduce the negative effects of noise on people and the environment.

14

The effect of sound-absorbing walls on the acoustic properties of the modelled unit cell of a sound-absorbing metamaterial

Chojak Aleksandra, Binek Wojciech, Chojnacki Bartłomiej, Pawlik Jan, Idczak Julia

Vibrations in Physical Systems

|

2023

|

Vol. 34, nr 2

art. no. 2023212

EN

Cavity-based metamaterials are usually designed for sound absorbing or sound scattering properties. They are built of combinations of ducts and slits, which in the case of acoustic absorbers are designed to maximize the sound absorption at resonance frequencies through the appearance of the viscothermal losses. The unit cells are designed under the assumption of perfectly rigid walls, shared by all the analytical models. Sound absorbing properties of the structures result from viscothermal losses in small ducts. The paper discusses the influence of adding sound absorption to the walls in the numerical model on the results of the observed sound absorption coefficient. It is demonstrated that the resulting sound absorption of the structure varies with changing sound absorption coefficient of the walls of the structure. The same observations are made for 3D-printed measurement samples, showing the importance of including the sound absorption of the walls in the modelling process.

15

Experimental verification of similarity criteria for sound absorption of simple metamaterials

Chojak Aleksandra

Vibrations in Physical Systems

|

2022

|

Vol. 33, nr 2

art. no. 2022211

EN

The paper concerns the dimensional analysis of simple acoustic metamaterials and its experimental verification in a computer model. Due to their decreased thickness possible because of the thermoviscous losses and sound dispersion that occur in acoustic metamaterials, such structures are gaining popularity, both as sound absorbers and diffusers. This implies the need to find their equivalents to be used at scale - both for modeling interiors with metamaterials and developing more complicated structures. The paper discusses the dimensional analysis performed for a generalized unit cell of a metamaterial with a resonator. The dimensional analysis shows the need for scaling both the geometrical dimensions of the structure and the parameters of the medium - air. The dimensional analysis was derived based on the transfer matrix method and was proven correct with the finite element method model. The paper also discusses the consequences of neglecting the air criteria, which are impossible to be fulfilled. This opens the question of finding new criterial numbers allowing the correct reflection of acoustic metamaterials at scale.

16

Comparative analysis of the acoustic properties of granular materials determined with the use of impedance tube

Kosała Krzysztof

Vibrations in Physical Systems

|

2022

|

Vol. 33, nr 3

art. no. 2022321

EN

The results of acoustic property tests for six types of granular materials: perlite, vermiculite, active coconut carbon, rubber granulates, pumice and wood chips, which can be used in noise protection structures, are shown in the article. The characteristics of the normal incidence sound absorption coefficient and the normal incidence sound transmission loss for material specimens with seven thicknesses in the range of 10-100 mm were determined based on the results of experimental tests carried out with the use of an impedance tube. The relationships between the first resonant absorption frequencies and the thicknesses of material specimens were determined. Single-number indices for the tested materials, in the form of the weighted sound absorption coefficients, were determined. Subsequently, dependencies of these indices on the surface mass of the tested materials were determined. The research showed that three materials, perlite, vermiculite and active coconut carbon, were distinguished among the examined granules with the best sound-absorbing and sound-insulating properties. Active coconut carbon had the best sound-insulating properties among the granular materials tested.

17

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

Czapla Marcjanna, Wszołek Tadeusz

Vibrations in Physical Systems

|

2022

|

Vol. 33, nr 1

art. no. 2022103

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.

18

A Novel Theoretical Modeling for Predicting the Sound Absorption of Woven Fabrics Using Modification of Sound Wave Equation and Genetic Algorithm

Putra Valentinus Galih Vidia, Irwan, Wijayono Andrian, Mohamad Juliany Ningsih, Yusuf Yusril

Autex Research Journal

|

2022

|

Vol. 22, no. 1

108--122

EN

Woven fabric in Indonesia is generally known as a material for making clothes and it has been applied as an interior finishing material in buildings, such as sound absorbent material. This study presents a new method for predicting the sound absorption of woven fabrics using a modification of the wave equations and using genetic algorithms. The main aim of this research is to study the sound absorption properties of woven fabric by modeling using a modification of the sound wave equations and using genetic algorithms. A new model for predicting the sound absorption coefficient of woven fabric (plain, twill 2/1, rips and satin fabric) as a function of porosity, the weight of the fabric, the thickness of the fabric, and frequency of the sound wave, was determined in this paper. In this research, the sound absorption coefficient equation was obtained using the modification of the sound wave equation as well as using genetic algorithms. This new model included the influence of the sound absorption coefficient phenomenon caused by porosity, the weight of the fabric, the thickness of fabric as well as the frequency of the sound wave. In this study, experimental data showed a good agreement with the model.

19

Experimental tests of the acoustic properties of sound-absorbing linings and cores of layered baffles

Kosała Krzysztof

Vibrations in Physical Systems

|

2021

|

Vol. 32, nr 1

art. no. 2021107

EN

The article presents the results of research on the acoustic properties of materials used as sound-absorbing linings and cores in baffles of anti-noise protection. Using an impedance tube the spectral characteristics of the normal incidence sound absorption and sound transmission loss indices of 12 specimens of mineral wool with different density and thickness were determined. From these characteristics, the single-number weighted sound absorption coefficient αw and the sound reduction index Rw were calculated. To calculate the value of the Rw index on the basis of surface mass of the mineral wool specimen, a new formula was proposed. The insertion loss of an acoustic enclosure with one, two and three-layer walls with dimensions of 0.7×0.7 m, containing mineral wool, was determined. The best efficiency was achieved for the enclosure made of walls of layers: mineral wool, placed on the sound source side, steel plate and aluminium plate.

20

Application of the impulse response method in the test of acoustic properties of building materials

Piechowicz Janusz

Vibrations in Physical Systems

|

2021

|

Vol. 32, nr 2

art. no. 2021201

EN

Understanding the acoustic properties of the materials used in the construction of wall surfaces, plays an important role in structural and environmental acoustics. There are many research methods for determining the acoustic parameters of building elements, such as the sound absorption coefficient, the sound reflection coefficient, or the sound insulation index determined in the laboratory or in situ. This work focuses on the determination of the sound absorption coefficient and the possibility of its measurement in "in situ" conditions by the impulse response method. The main purpose of the presented research was to check whether it is possible to use the impulse method in a small reverberant room to determine the sound absorption coefficient of a small part of the wall structure.