A Comparative Study of Performances of Different Types of Barrier Constructions for Attenuating Low Frequency Noise

Abstract

Low frequency sounds and vibrations are associated mostly with rotary machines, which are the most common ones, seen from workplaces like factory lathe machines, milling machines, etc., to machineries like pumps, fans, generators etc., to vehicles like cars, trains, airplanes etc., in one words, almost everywhere. When the sound pressure level of these low frequency sounds is not within a tolerable range, it is considered as noise and it must be controlled in order to protect human ear from its hazardous effects. Low frequency noise can be controlled in many ways; one of the ways is restricting the noise from reaching human ear i.e. using barriers. The problem faced by barriers in restricting of low frequency noises is that they have a high wavelength, making them likely to pass through barriers easily and less chance of reflection. Also, the absorption coefficient of a material is inversely proportional to the wavelength, therefore low absorption possibility for low frequency noises. To solve these problems, the mass of the barrier is increased following mass low, which increases cost. In the present study, it has compared the transmission losses due to two types of commonly used barrier constructions, Double layer type barriers and Sandwich type barriers and determined which one has better performance in attenuating low frequency noise. Also, for construction, two different types of absorbing materials, glass wool and PE foam is used to account for material variations.

Keywords

• Noise Barrier
• Transmission Loss
• Low Frequency Noise
• Noise Attenuation
• Sound Pressure Level
• Mass Law
• Critical Frequency
• Coincidence region

How to cite

Abid Hossain Khan, Md. Mostofa Hossain (2016). A Comparative Study of Performances of Different Types of Barrier Constructions for Attenuating Low Frequency Noise. Sonargaon University Journal, 1(2), 108–123.

@article{khan20169,
  title   = {A Comparative Study of Performances of Different Types of Barrier Constructions for Attenuating Low Frequency Noise},
  author  = {Abid Hossain Khan and Md. Mostofa Hossain},
  journal = {Sonargaon University Journal},
  volume  = {1},
  number  = {2},
  pages   = {108--123},
  year    = {2016},
  issn    = {2518-3125},
  url     = {https://su.edu.bd/journal/volume-1-number-2/a-comparative-study-of-performances-of-different-types-of-barrier-constructions}
}