Measuring Methods of Acoustic Properties and Influence of Physical Parameters on Natural Fibers: A Review

ABSTRACT

Nowadays, the world becomes more contaminated due to various factors such as pollution, global warming and unhealthy human practices. In this review paper, noise pollution is taken into major concern which affects quality of human life. Many researchers had attempted many studies to optimize the sound-absorbing capacity of natural fibers and to replace use of non-biodegradable synthetic sound barriers. This review research also focuses on the measurement of acoustic absorption coefficient (AAC) through various analytical such as Delany–Bazley, Garai–Pompoli and Biot–Allard method and experimental approaches such as impedance tube, reverberation room and environment anonymous (EA) noise. In addition to that, the influence of physical parameters such as fibrous material’s thickness, density and porosity are also reviewed. It was found that most of the reviewer used two microphone impedance test tubes for determining absorption coefficient (α) of natural fiber-reinforced laminates. The more denser, thicker and porous materials shows better absorption rate than less denser, thicker and porous materials due to its high polymerization blending. Finally, these measuring methods are used to enhance the properties such as absorbing and reflecting in applications like sound recording room, acoustic baffles, damping sheets, barrier decoupler, etc.

摘要

如今，由于污染、全球变暖和不健康的人类行为等各种因素，世界变得更加污染.本文综述了噪声污染对人类生活质量的影响.许多研究人员尝试了许多研究，以优化天然纤维的吸声能力，并取代使用不可生物降解的合成声屏障.本文还着重介绍了用Delany Bazley、Garai Pompoli、Biot Allard等多种分析方法和阻抗管、混响室、环境匿名（EA）噪声等实验方法测量吸声系数（AAC）的方法.此外，还对纤维材料的厚度、密度和气孔率等物理参数的影响进行了综述.研究发现，大多数研究者使用两个传声器阻抗测试管来测定天然纤维增强层合板的吸收系数（α）.密度越大、厚度越厚、多孔材料由于具有较高的聚合共混性，其吸附速率比密度越小、厚度越厚、多孔材料的好.最后，将这些测量方法应用于录音室、隔音板、阻尼片、屏障去耦器等应用中，以提高其吸收和反射等性能.

KEYWORDS:

• Measurement techniques
• acoustic absorption coefficient
• physical parameters

关键词:

• 测量技术
• 吸声系数
• 物理参数.

Title and Central theme of the article

In this environmental degrading world, noise pollution has its ripple effect on lives of human beings. The interior control of noise has been notably improving in order to save future generations. But at the same time, the advanced materials should also balance the development and applications where it is being used. In addition, the materials should not harm human beings at any cost.

This present review work mainly focuses on sound absorption analysis on different natural fibers. This work helps researcher to select new class of fibers and their affecting parameters in order to enhance the sound proofing quality and decreasing effect on human ears.

Prime Novelty Statement

This work consists of new kind of tabular formation that expresses more information on natural fiber efficiency on acoustical performance. This work has not been attempted earlier in this specified format.

Declaration of Interest

The authors solemnly declare that they have no conflict of interest. This work has not been published or presented anywhere.