Characteristics of coconut coir fiber acoustic panel at low high frequencies

Abstract

The most frequent problems faced by noise control engineer are how to design sound absorber panel that provide the desirable sound absorption coefficient that minimizes the size and cost. Sound absorber panel can absorb incident sound energy, which has been not reflected from its surface. Therefore, reflected sound energy must be as low as possible. Consequently this requires sufficient thickness. The main objective of this research is to A.'710W about basic characteristic of noise absorption coefficient for material that is made with organic fiber material (coconut coir fiber) at low and high frequencies. The mail! parameters in this research are the material thickness. The noise absorption characteristics of samples tested using the impedance tube method. The device set includes the low and high frequency tubes with samples holders, loudspeakers case and audio amplifier, two microphones and supply sets. A user-friendly software interface ( SCS81 00) guides the user through the measurement and the store and print operations of the results. Test samples providedfrom coconut coirfiber, shaped cylindrical with diameter 100 111m and 28 mm. The samples thickness 10 mm, 20 mm, 30 mm, 40 mm, and 50 111m respectively. Latex was used to provide the requirement cohesive between the coir fibers. From the experimental data showed that at low frequencies, the higher thickness of the sample, the bigger is the noise absorption coefficient. At high frequency, samples with 50 mrn thickness have the highest noise absorption coefficient about 0.95 at frequency 1700 }{z. Keywords: Coconut coir fiber; low frequency; high frequency; noise absorption coefficient