A Review on the Acoustic Absorption Performance of Various Granular Materials- the Cost-effective Acoustic Absorbers for Commercialization

Abstract

The utilization of recycled rubber and natural granular materials in the production of acoustic absorbers can help the vicinity of solving the problem of the disposal of waste material and noise pollution. The present paper reviews the analytical and experimental analyses of various granular materials aimed at the determination of their acoustic properties in terms of various analytical models. The acoustic absorption performance of the traditional rubber and natural granular materials was investigated in terms of grain sizes, flow resistivity and sound absorbing coefficient. The study reported that the effectiveness of the acoustic absorption performance of the granular materials increases with decrease in their sizes. The acoustic absorption performance of rubber crumbs, pine saw dust and rice husk have reported as good acoustic materials with a broad band absorption spectrum. The acoustic absorption performance of the above mentioned granular materials help to determine the potential of biomass granular material as a sustainable and cost effective acoustic absorber to be used at indoor and outdoor applications for sound absorption purpose. This review aimed to investigate the potentially applicable analytical approaches in order to understand the sound absorption properties of recycled waste granular materials. Furthermore the study contributes to the body of knowledge of the beneficial way of waste management by confronting the volatile price of traditional acoustic absorber. The insights of the paper may service for the business sector managers to commercialize the said concept and operational content to gain competitive advantages through cost effectiveness.