Investigation of natural material to reduce industrial noise

Abstract

Today with rapid industrialization, industrial noise has become a serious environmental problem in Sri Lanka. The noise which is generated by machines in industry is called as industrial noise. This excessive noise can interfere with communication between supervisors and employees. Continuous exposure to noise can cause fatigue, which often results in accidents and reduces the pace and quality of work. Noise affects negatively on the day today life of surrounding people, who have faced with many problems mentally and physically. Therefore, noise control is one of the major requirements to improve the living environment. Most of the developed countries use practical techniques to minimize the nuisance such as barrier walls, duct silencers, acoustical wall panel, soundproof curtains, sound enclosures for industrial machinery and other similar noise control treatments that are installed near the source to effectively reduce the sound level. However, Sri Lanka has not yet yielded much into this issue as noise reduction methods are costly. Therefore, it is necessary to find out cost effective methods to control industrial noise. This research was conducted to investigate the potential uses of Salvinia dust as natural sound reduction material, to give a solution for the existing industrial noise problems. Specimens having a size of 75 mm (diameter) x 25 mm (thickness) were made by using Salvinia dust. Salvinia dust was mixed with cement at a ratio of 1:1 and water was added. Noise Reduction Coefficient of these specimens were investigated by using an experimental set-up including signal generator, speaker and noise level meter. Noise reduction ability of the materials was quantified by using Noise Reduction Co-efficient (NRC). Variation of NRC with particle size, mix proportion and sample thickness were also investigated. Effectiveness of Salvinia dust to control industrial noise is discussed in this paper.