A review on physical factors influencing absorption performance offibrous sound absorption material from natural fibers

Noise pollution is one of the major threats in many countries that affect our quality of life. This problem can cause negative effect to human hearing, disturbing emotion as well as individual behavior. Noise can be treated and control by applying sound insulation or sound barriers at affected areas. Many studies attempt to optimize the use of natural fibers as sound insulation materials replacing readily available synthetic products in the market. Natural fibres such as rice straw, coconut coir, palm oil, tea-leaf, kenaf, hemp, bamboo, cotton, wood particle, wool and clay is biodegradable, renewable, cheap and give less potential risk to human health. Utilization of these materials as sound insulation product will give practical solutions in waste management issues. This paper review on the factors that influencing absorption performance of natural fibrous sound absorbing materials. Physical properties such as fiber thickness, density and porosity are the main factor that contributes to sound absorption performance of natural fibers. It was found that most of natural fibers are capable to absorb sound in wide range of frequencies. Thicker panels are good for low frequency application while thinner absorbent is best for high frequency. Moreover, denser materials absorbed more sound energy compared to less dense materials. Significant effect on sound absorption performance was also given by materials with less porosity compared to materials which have more pores