scholarly journals The design of an impedance tube and testing of sound absorption coefficient of selected materials

2021 ◽  
Vol 1050 ◽  
pp. 012003
Author(s):  
R Ďuriš ◽  
E Labašová
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Sound Absorption Coefficient ◽  
Impedance Tube

Sound Absorption Characteristics of Porous Steel Manufactured by Lost Carbonate Sintering

2009 ◽  
Vol 1188 ◽  
Author(s):  
Miao Lu ◽  
Carl Hopkins ◽  
Yuyuan Zhao ◽  
Gary Seiffert
Keyword(s):  
Absorption Coefficient ◽  
Pore Size ◽  
Sound Absorption ◽  
Single Layer ◽  
Normal Incidence ◽  
Sound Absorption Coefficient ◽  
Absorption Coefficients ◽  
Impedance Tube ◽  
Absorption Characteristics

AbstractThis paper investigates the sound absorption characteristics of porous steel samples manufactured by Lost Carbonate Sintering. Measurements of the normal incidence sound absorption coefficient were made using an impedance tube for single-layer porous steel discs and assemblies comprising four layers of porous steel discs. The sound absorption coefficient was found not to vary significantly with pore size in the range of 250-1500 μm. In general, the absorption coefficient increases with increasing frequency and increasing thickness, and peaks at specific frequencies depending on the porosity. An increase in porosity tends to increase the frequency at which the sound absorption coefficient reaches this peak. An advantage was found in using an assembly of samples with gradient porosities of 75%-70%-65%-60% as it gave higher and more uniform sound absorption coefficients than an assembly with porosities of 75%.

The Process Development for Sound Absorption Design of Non-Woven Car Mat

2020 ◽  
Vol 305 ◽  
pp. 43-48
Author(s):  
Un Hwan Park ◽  
Jun Hyeok Heo ◽  
In Sung Lee ◽  
Dae Kyu Park
Keyword(s):  
Absorption Coefficient ◽  
Physical Properties ◽  
Sound Absorption ◽  
Process Development ◽  
Sound Absorption Coefficient ◽  
Development Effort ◽  
Reverberation Chamber ◽  
Impedance Tube ◽  
Impedance Tubes ◽  
Automotive Interior

Automotive interior material with consists of several material layers has the sound-absorbing function. It is difficult to predict sound absorbing coefficient because of several material layers. So, many experimental tuning is required to achieve the target of sound absorption. Therefore, while the car interior materials are developed, a lot of time and money is spent. In this study, we present the method to predict the sound absorbing performance of the material with multi-layer using physical properties of each material. The properties are predicted by foam-X software using sound absorption coefficient data measured by impedance tube. And we will compare and analyze the predicted sound absorption coefficient with the data measured by scaled reverberation chamber and impedance tubes for a prototype. If the method is used instead of experimental tuning in the development of car interior material, the time and money can be saved. And then, the development effort can be is reduced because it can be optimized by simulation.

scholarly journals Development of Impedance Tube to Measure Sound Absorption Coefficient

2019 ◽  
Vol 8 (6) ◽  
pp. 3218-3222
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Acoustic Property ◽  
Small Sample ◽  
Textile Material ◽  
Acoustic Properties ◽  
Sound Absorption Coefficient ◽  
Impedance Tube ◽  
Significant Difference

An acoustic property of textile material can be measured using an impedance tube, is the most popular technique to measure normal sound absorption and transmission loss. This method consuming less time and a very small sample is required to assess the acoustic properties of the materials. Unfortunately, the cost of the impedance tube and software used for measurement is very high. This paper gives information about how to develop a cost-effective impedance tube suitable for researchers. The design, development, and fabrication of the impedance tube suitable for different frequencies with technical details are present here. Information related to some software which can be used to measure sound absorption coefficient also provided. To validate the testing results obtained from custom-build impedance tube, same samples were tested on commercially available impedance tube at PSG College, Coimbatore. It was observed that both the instruments provide almost same results, no statistically significant difference found in results. Base on the results design of customized impedance tube recommends to student and researcher interested in measuring acoustic properties of textile material

Development of an Indigenous Impedance Tube

2015 ◽  
Vol 786 ◽  
pp. 149-155
Author(s):  
Wei Hong Tan ◽  
Rosmaini Ahmad ◽  
Nur Hafizah Zunaidi ◽  
Ruslizam Daud ◽  
E.M. Cheng
Keyword(s):  
Transfer Function ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Function Method ◽  
Theoretical Background ◽  
Sound Absorption Coefficient ◽  
Frequency Range ◽  
Cavity Depth ◽  
Impedance Tube ◽  
Transfer Function Method

Fabrication of an impedance tube for measuring sound absorption coefficient is presented in this paper. Transfer-function method is chosen for the sound absorption analysis. The impedance tube is designed and fabricated in accordance with ISO 10534-2. The tube is made from brass with diameter of 114.3 mm and length of 1.42 m. It is designed for the frequency range 60 Hz to 1800Hz. Three microphone positions are installed to achieve the frequency range with a single tube. The theoretical background of transfer-function method between two microphones is discussed. Initially, impedance tube is characterized by the measurement without testing material in the tube. Micro-perforated panel (MPP) with 50 mm and 100 mm of cavity depth are used for measurement. The sound absorption coefficient measurement of the MPP is compared with theory and good agreement is achieved. Various problems related to design and construction is addressed and the optimal configuration is presented.

scholarly journals STUDY AND ANALYSIS ON SOUND ABSORBING AND NOISE REDUCING PERFORMANCE OF TIMBER CONSTRUCTION WALL BASED ON ACOUSTIC SPIRAL MATASURFACE

Wood Research ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 341-352
Author(s):  
Haiyan Fu ◽  
Xinyue Zhao ◽  
Patrick Adjei ◽  
Zheng Wang ◽  
Xiaoli Wu
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Low Frequency ◽  
Sound Absorption Coefficient ◽  
Impedance Tube ◽  
Frequency Sound ◽  
Timber Construction ◽  
Absorption Performance ◽  
Impedance Tube Method ◽  
Structural Layer

Based on acoustic spiral metasurface, a spiral structural layer was designed to apply to timber construction interior wall. The sound absorption coefficient was measured by impedance tube method and compared with Helmholtz resonance structural layer, solid structural layer and air layer in traditional wall. The results show that the combination of the spiral structural layer and the wall can optimize the sound absorption performance of the wall in the medium and low frequency. Without reducing the overall sound-absorbing performance of the wall, can achieve perfect sound absorption in some medium and low frequency sound bands.

scholarly journals A new simple method for determining the sound absorption coefficient

2018 ◽  
Vol 211 ◽  
pp. 04003
Author(s):  
Merab Chelidze
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Sound Propagation ◽  
Sound Absorption Coefficient ◽  
Measuring Instruments ◽  
Sound Waves ◽  
Simple Method ◽  
Impedance Tube ◽  
Wide Range ◽  
Low Sensitivity

Taking into account the influence of the length and diameter of the impedance tube on the process of decay of sound waves, a new study of sound propagation in an impedance tube is presented, on the basis of which it is easier to determine the sound absorption coefficient. The new simple method of determining the absorption coefficient, based on the decay of reverberating waves, is fairly stable and demonstrates a low sensitivity for all errors made in the measurement. The presented method makes it possible to measure the sound absorption coefficient without laboratories and precision measuring instruments in a wide range at the level of separate consumers.

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