eng Ansari Education and Research Society Journal of Ultra Scientist of Physical Sciences July 2018 30 7 72 80 http://dx.doi.org/10.22147/jusps-B/300701 1481 article SREEJA RAJAPPAN 1 PREMLET BHASKARAN 2 ROXY. M.S 2 Government Polytechnic College, Kalamassery, Eranakulam, Kerala (India) S.N. College, Kollam, University of Kerala, Thiruvananthapuram, Kerala, (India) <p style="margin-left:40px; text-align:justify">Active and passive noise controlling methods are widely used for noise reduction applications as it is essential to control unwanted noise and vibration which adversely affects human life, wild life, aquatic life and the ecosystem as such. The technological, automobile and biomedical world also prefer noise and vibration free atmosphere for the efficient performance. However, passive noise reduction at lower frequency range is highly challenging due to the unavailability of suitable materials. The emergence of engineered composite materials pave way to this bottle neck problem. Herein, natural fiber composites are synthesized using Vacuum Assisted Resin Transfer Molding and characterized for noise reduction in the low frequency region with the help of transfer matrix method using an impedance tube. The results show that the natural micro fibrous basalt fiber composite is a highly efficient sound absorber in the lower frequency region compared to the glass fiber based one. The fiber radius is critical in tuning the frequency range. The contact angle measurements reveals that the basalt fiber composite is more hydrophobic in nature.</p> https://ultraphysicalsciences.org/paper/1481/ noise reduction passive acoustic absorber acoustic absorption coefficient