Research on attenuation of sound waves by using panels made of composite materials

Noise is a well known source of environmental pollution in urban areas or at work. Sound pressure level has a harmful effect on human health. In this paper we present our research on making a new type of composite material and testing its properties of noise attenuation level. Tests were carried out in the anechoic chamber using barrier attenuators of sound waves made of composite material consisting of 50% formaldehyde resin reinforced polypropylene granules formed from waste 50%. It was also determined the efficiency of the panel by calculating the diffraction pression according to the sound waves dispersion on the acoustic panel's surface and mapping the attenuation of noise levels due to the composite material.