Influence of Density on Sound Absorption Coefficient of Fibre Board

Abstract

For acoustic applications such as theaters, cinema halls, auditoriums the data on acoustic properties i.e. sound absorption coefficient and sound transmission loss are required to evaluate the acoustic behavior of panel products and to facilitate the necessary design computations. Fibre boards are widely used in private and commercial buildings, but not much data are available on acoustic efficiency of fibre boards. The study was carried using acoustic pulse tester based on standing wave method for evaluating sound absorption coefficient. Wood fibre boards of different densities ranging from 200 to 800 kg/m 3 were taken and their sound absorption coefficients at frequencies ranging from 125 Hz to 4000 Hz were evaluated in third octave band. Noise reduction coefficient of the samples was also computed. From the study, it is observed that low density fibre board possess high sound absorption coefficient and noise reduction coefficient when compared with high density fibre boards. It was seen that sound absorption coefficient increases with decrease in density and vice versa.

On the Role of Acoustical Improvement and Surface Morphology of Seashell Composite Panel for Interior Applications in Buildings

“…In the 30 mm ones, Placuna placenta shell has a wider broadband frequency than the other two shells. Associated with density material, this result is in accordance with other research conducted by Nandawar et al, [25] where decreasing density on fiber boards improves sound absorption ability (see Figure 3). Placuna placenta with 30 mm thick and density 1.392 gram/cm 3 had the best sound absorption followed by Anadara granosa with density 1.643 gram/ cm 3 .…”

“…Research by Wang and Torng [23] and Latief, et al found the increment of density could increase the sound absorption coefficient in low frequencies [24]. Different results were released in research by Nandanwar, et al where low density fiber boards possess a higher sound absorption coefficient than high density fiber boards [25]. For research on the effect of density on Sound Transmission Loss performance (STL), two studies conducted by Ko, et al and Narang identified that additional cavities on the metal material could improve the STL performances [26,27].…”

“…Acoustical response of wool board was reported by Hua and Enhui (2017) [22], while glass fiber and rockwool materials and high desinty bio-polymer foam (HDBP) were reported by Wang and Trong (2001) [23] and Latief et al (2014) [24] respectively. Another research by Nandanwar et al (2017) [25] showed that lower density fiber board posed a better sound absorption performance compared to similar board with a higher density. In regards to the use of cavity inclusion, Narang (1993) showed that the addition of a cavity to the metal frame could improve STL to the limit of 10 dB [26], while a similar result was reported by Ko et al (2007) who proposed that aluminum foam material could have high sound transmission loss if it was treated with the addition of a cavity to the structure [27].…”

Acoustical properties of wood fiberboards prepared with different densities and resin contents

“…The sound absorption coefficients of all the specimens increased as the frequency increased, in line with the results obtained for typical porous sound-absorbing materials such as glass wool and rock wool (Or et al 2017). The sound absorbing ability of a material depends on the amount of air trapped in its pores because of the friction that generates between the incident sound energy and the air layer inside the material (Nandanwar et al 2017). When comparing fiberboards D-1 through D-3, higher sound absorption ability was observed for the least dense sample, due to its higher porosity (D-1: 89.7%, D-2: 86.2%, D-3: 83.0%).…”

Music for cells? A systematic review of studies investigating the effects of audible sound played through speaker-based systems to cell cultures

“…Sound waves can travel through different mediums, including gas, liquid, and solids, but with different speeds dependent on the medium. Typically, sound travels faster in a liquid or solid medium, for example, water or a steel bar, than in gas medium (20)(21)(22)(23).…”