Reviews in Sound Absoring Materials
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Review in Sound Absorbing Materials
X. Sagartzazua,*, L. Hervellab, and J. M. Pagaldaya
a
Ikerlan, Mechanical Engineering Area. Pº Arizmendiarrieta, 2. 20500 Arrasate-Mondragón. Spain. Tel: 0034 943 712400. Fax: 0034 943 796944
b
Universidade da Coruña, Facultade da Informática, Department of Mathematics. Campus Elviña. Spain. Tel: 0034 981167000 (ext. 1325). Fax: 0034.981167160
*
Corresponding autor. Email adresses: xsagartzazu@ikerlan.es (X. Sagartzazu), luisher@udc.es (L. Hervella), jmpagalday@ikerlan.es (J. M. Pagalday).
ABSTRACT
This article is a bibliographical revision concerning acoustic absorbing materials, also known as poroelastics. These absorbing materials are a passive medium use extensively in the industry to reduce noise. This review presents the fundamental parameters that define each of the parts comprising these materials, as well as current experimental methods used to measure said parameters. Further along, we will analyze the principle models of characterization in order to study the behaviour of poroelastic materials. Given the lack of accuracy of the standing wave method three absorbing materials are characterized using said principle models. A comparison between measurements with the standing wave method and the predicted surface impedance with the models is shown.
KEY WORDS: poroelastic material, acoustic surface impedance, poroelastic characterization, models, sound absorption
1.
INTRODUCTION
The number of products that include a low noise level design increases daily. However, apart from the design itself, it is frequently necessary to use techniques that lower the level of noise in the product or industrial application.
A variety of methods are available for noise reduction but they can be basically grouped as follows: passive and active mediums. Active mediums differ from passive mediums in that it is necessary to apply external energy in the noise reducing process. The
Review in Sound Absorbing Materials
X. Sagartzazua,*, L. Hervellab, and J. M. Pagaldaya
a
Ikerlan, Mechanical Engineering Area. Pº Arizmendiarrieta, 2. 20500 Arrasate-Mondragón. Spain. Tel: 0034 943 712400. Fax: 0034 943 796944
b
Universidade da Coruña, Facultade da Informática, Department of Mathematics. Campus Elviña. Spain. Tel: 0034 981167000 (ext. 1325). Fax: 0034.981167160
*
Corresponding autor. Email adresses: xsagartzazu@ikerlan.es (X. Sagartzazu), luisher@udc.es (L. Hervella), jmpagalday@ikerlan.es (J. M. Pagalday).
ABSTRACT
This article is a bibliographical revision concerning acoustic absorbing materials, also known as poroelastics. These absorbing materials are a passive medium use extensively in the industry to reduce noise. This review presents the fundamental parameters that define each of the parts comprising these materials, as well as current experimental methods used to measure said parameters. Further along, we will analyze the principle models of characterization in order to study the behaviour of poroelastic materials. Given the lack of accuracy of the standing wave method three absorbing materials are characterized using said principle models. A comparison between measurements with the standing wave method and the predicted surface impedance with the models is shown.
KEY WORDS: poroelastic material, acoustic surface impedance, poroelastic characterization, models, sound absorption
1.
INTRODUCTION
The number of products that include a low noise level design increases daily. However, apart from the design itself, it is frequently necessary to use techniques that lower the level of noise in the product or industrial application.
A variety of methods are available for noise reduction but they can be basically grouped as follows: passive and active mediums. Active mediums differ from passive mediums in that it is necessary to apply external energy in the noise reducing process. The