Sound Absorption Coefficient of Different Green Materials Polymer on Noise Reduction

Abstract

One of the sources of noise pollution to environment is from the consumption of electrical and mechanical appliances usage at home and industries. Growth development and advancement of heavy equipment in construction work further emphasize the necessity used of new technologies for noise reduction. The best technique of control or reducing of noise is by using the materials that can absorb the noise by materials itself. Potential materials from agricultural waste as sound absorber were identified. There are two main objectives in this study; First is to produce acoustic absorber by using natural materials. Second is to identify their sound absorption coefficients. The samples were fabricated using the raw materials from banana stem, grass, palm oil leaves and lemongrass mixed with binding agents of polyurethane and hardener to the ratio of 1:4. The diameters of the samples consist of 28mm and 100mm and the thickness is 10mm. The samples sound absorption coefficients were measured according to standards ASTM E1050-98 / ISO 105342-2 (Impedance tube method). Sound absorption coefficient of the materials depends on frequencies choose. The frequencies values used in this study were in the range from 500Hz to 4500Hz. Material made from grass have a higher average sound absorption coefficient value which is 0.553. All tested samples also can be categories under class D type of materials based on sound absorption coefficient value.

Acoustic Performance of Porous Mortar and Potential Use for Traffic Noise Mitigation: A Review

“…IT testing exhibits more accuracy due to less sound diffraction effect on samples [26]. The results of these two tests can determine the nature of sound absorption, that is by examining the SAC curve but the noise reduction coefficient (NRC) which is the average value of sound frequencies at 250 Hz, 500 Hz, 1000 Hz and 2000 Hz [27], can determine the quality of an efficient sound absorber if the value is 0.45 [28]. SAA, which is the average at 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz determines the ability of the material with a value above 0.2 as a good material as a sound absorber.…”