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Noise contributes as a source of heart attacks, besides annoyance, hypertension and sleep disturbance. In order to overcome such problems, an effective and efficient noise control is required. To control the industrial noise, sound absorbers are used by reducing their energy by using sound absorbers. This application is also used in buildings to control the quality of acoustics inside a room for smooth communication and interaction with others. Common absorbers that are widely used are perforated plates, fibrous porous materials like coir, polyester, melamine. It has been found that such materials have good sound absorption performance at almost all frequencies. Absorption coefficient is used to measure the sound absorbed by a material. There are different models and approaches for calculating the absorption coefficient of sound absorber materials like perforated plates and porous materials. Absorption coefficient is a function of frequency, porosity, viscous length, thermal length, tortuosity and flow resistivity. Many classical models have been developed for calculating the absorption coefficient of configurations using above materials, by altering the geometrical parameters, involved in multilayer use of these materials. This paper analyses the calculation of absorption coefficient using different models and for different combination of perforated plates, air cavity and porous materials. To start with, total eight configurations have been taken for examination using transfer matrix (TM) method to estimate absorption coefficient. Johnson-Champoux-Allard (JCA), Atalla-Sgard and Miki model have been used to estimate acoustic impedance of porous material. Next, the acoustic impedance for all configurations have been estimated using acoustic impedance transfer (IT) methods. The agreement and disagreement between estimated results from TM and IT have been further judged against experimental investigations.
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