Predicted sound absorption coefficients of absorber materials lined in a chamber

Forouharmajd, Farhad; Nassiri, Parvin; Monazzam, Mohammad Reza; Yazdchi, Mohammadreza

doi:10.4103/2277-9183.132685

Predicted sound absorption coefficients of absorber materials lined in a chamber

Document Type : Original Article

Authors

Farhad Forouharmajd ¹

Parvin Nassiri ²

Mohammad Reza Monazzam ²

Mohammadreza Yazdchi ³

¹ Department of Occupational Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan; Department of Occupational Hygiene, School of Public Health and Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran

² Department of Occupational Hygiene, School of Public Health and Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran

³ Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran

10.4103/2277-9183.132685

Abstract

Aims: The present study was aimed to measurement of sound absorption coefficient of mineral wool and determination of their absorption ability. Materials and Methods: Mineral wool was used to find noise absorption coefficient. Random and normal sound absorption coefficient values were predicted. Then, the measures of transmission loss calculated as an overall value, for applied absorbent material and bare sheet metal. Results: The measured values of noise with one octave band frequency demonstrated an attenuation of 5.5-7 dB for these frequencies. The absorption coefficients of materials showed that mineral wool had more normal sound coefficients than its random sound absorption coefficient values. Conclusion: It can be concluded that predicted normal sound absorption coefficients of used mineral wool materials were near to the areas of standard line. It seems that the amount or thickness of absorbent lining was a main reason of noise reduction in low band frequencies. Mineral wool has a higher density and can provide better acoustical and insulating results than fiberglass. Besides, mineral wool doesn't lose its insulating value when wet and has an outstanding resistance to fire.

Keywords

Absorption coefficient

mineral wool

noise

transmission loss