Microphone-free measurement of acoustic absorption coefficient of materials using a standing wave tube

2005 ◽  
Vol 16 (5) ◽  
pp. 1069-1074 ◽  
Author(s):  
Dewei Peng ◽  
Shih-Fu Ling
Keyword(s):  
Absorption Coefficient ◽  
Standing Wave ◽  
Acoustic Absorption ◽  
Wave Tube ◽  
Acoustic Absorption Coefficient ◽  
Standing Wave Tube

A New Method to Measure the Absorption Coefficient of the Automotive Driving Room Based on the Sound Pressure Delaying

2011 ◽  
Vol 415-417 ◽  
pp. 1350-1354
Author(s):  
Cong Yun Zhu ◽  
Jian Ru Shi ◽  
Shu Feng Yang
Keyword(s):  
Absorption Coefficient ◽  
Standing Wave ◽  
Sound Pressure ◽  
Measurement Methods ◽  
The Other ◽  
New Method ◽  
Wave Tube ◽  
Absorption Function ◽  
Equal Distance ◽  
Standing Wave Tube

Absorption coefficient is an important parameter of the absorption function of the absorption material. Traditional measurement methods of absorption coefficient are standing wave tube and reverberation which have some shortcomings. In this paper, phase of the sound pressure measured by two equal distance microphones placed in the front of the absorption material is delayed in order to attain the absorption coefficient. At the last, an experiment for one absorption material is carried out, the experiment results compare with the results of the other methods above mentioned that denotes that the theory is correct and practicable.

A New Method to Measure the Absorption Coefficient Based on the Sound Pressure Delaying

2013 ◽  
Vol 834-836 ◽  
pp. 1156-1160
Author(s):  
Da Yu Huang
Keyword(s):  
Absorption Coefficient ◽  
Standing Wave ◽  
Sound Pressure ◽  
Measurement Methods ◽  
Reverberation Time ◽  
Wave Tube ◽  
Absorption Function ◽  
Equal Distance ◽  
Key Words Absorption ◽  
Standing Wave Tube

Absorption coefficient is an important parameter of the absorption function of the absorption material. Traditional measurement methods of absorption coefficient are standing wave tube and reverberation which have some shortcomings. In this paper, phase of the sound pressure measured by two equal distance microphones placed in the front of the absorption material is delayed in order to attain the absorption coefficient. At the last, an experiment for one absorption material is carried out, the experiment results compare with the results of the other methods above mentioned that denotes that the theory is correct and practicable. Key words: absorption material standing wave reverberation time delaying

Low-frequency sound absorption of a tunable multilayer composite structure

2021 ◽  
pp. 107754632110082
Author(s):  
Hanbo Shao ◽  
Jincheng He ◽  
Jiang Zhu ◽  
Guoping Chen ◽  
Huan He
Keyword(s):  
Porous Material ◽  
Absorption Coefficient ◽  
Composite Structure ◽  
Low Frequency ◽  
Acoustic Absorption ◽  
Multilayer Composite ◽  
Absorption Frequency ◽  
Acoustic Absorption Coefficient ◽  
Simulation And Experiment ◽  
Single Material

Our work investigates a tunable multilayer composite structure for applications in the area of low-frequency absorption. This acoustic device is comprised of three layers, Helmholtz cavity layer, microperforated panel layer, and the porous material layer. For the simulation and experiment in our research, the absorber can fulfill a twofold requirement: the acoustic absorption coefficient can reach near 0.8 in very low frequency (400 Hz) and the range of frequency is very wide (400–3000 Hz). In all its absorption frequency, the average of the acoustic absorption coefficient is over 0.9. Besides, the absorption coefficient can be tunable by the scalable cavity. The multilayer composite structure in our article solved the disadvantages in single material. For example, small absorption coefficient in low frequency in traditional material such as microperforated panel and porous material and narrow reduction frequency range in acoustic metamaterial such as Helmholtz cavity. The design of the composite structure in our article can have more wide application than single material. It can also give us a novel idea to produce new acoustic devices.

The effect of the combination of multiple woven fabric and nonwoven on acoustic absorption

2019 ◽  
pp. 152808371985877 ◽  
Author(s):  
Pilar Segura-Alcaraz ◽  
Jorge Segura-Alcaraz ◽  
Ignacio Montava ◽  
Marilés Bonet-Aracil
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Woven Fabric ◽  
Sound Absorption Coefficient ◽  
Acoustic Absorption ◽  
Experimental Conditions ◽  
Resistive Layer ◽  
Textile Materials ◽  
Acoustic Absorption Coefficient ◽  
Fabric Structures

Textile materials can be used as acoustic materials. In this study, the acoustic absorption coefficient of multilayer fabrics with 60 ends/cm and 15, 30, 45, and 60 picks/cm is measured when the fabric is added as a resistive layer on top of a polyester nonwoven, in order to study the influence of the fabric spatial structure in the acoustic absorption of the assembly. Five different fabric structures are used. Design of experiments and data analysis tools are used to describe the influence of two manufacturing factors on the sound absorption coefficient of the ensemble. These factors are the fabric weft count (picks/cm) and the thickness of the nonwoven (mm). The experimental conditions under which the maximum sound absorption coefficient is achieved are found. The influence of each factor and a mathematical model are obtained. Results of statistical and optimization analysis show that for the same fabric density, sound absorption coefficient increases as the number of layers decreases.

Laboratory measurement of the acoustic absorption coefficient based on the modal dispersion

2013 ◽  
Vol 134 (5) ◽  
pp. 4004-4004
Author(s):  
Jevgenija Prisutova ◽  
Kirill Horoshenkov ◽  
Jean-Philippe Groby ◽  
Bruno Brouard
Keyword(s):  
Absorption Coefficient ◽  
Laboratory Measurement ◽  
Acoustic Absorption ◽  
Modal Dispersion ◽  
Acoustic Absorption Coefficient
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