Abstract: A comparison between acoustic sound absorption coefficient and transmission loss index of absorption panel using natural organic multi-layer coir fibre as the filler with and without perforated panels were studied this research. Experimental data obtained using reverberation room test method were compared with data from numerical simulation. The innovative sound absorption panel was developed and fabricated using treated coir fibre layers as sound absorption materials. The outer layer of the panel was fabricated from natural fibre/polyester composite panel. This innovative acoustic panel was tested at acoustic lab, faculty of engineering, Universiti Kebangsaan Malaysia using ISO 354 (1985) standard for noise absorption coefficient and ISO 717-1 standard for the transmission lost index. Simulation study was also conducted for the sound absorption panel using the Win FLAGTM software. For the sound absorption coefficient, the experiment gives the value between 0.70 and 0.80 for the frequency range of 1000 to 1800 Hz while the sound absorption coefficient obtained from simulation gives 0.7 to 0.85 for the frequency range of 500 to 2500 Hz. Transmission lost index gives an average of 20 dB for the panel. The results showed that the sound absorption coefficient obtained through both the experimental and simulation methods were comparable to those use commercially in the market such as rock wool and synthetic fibres.