Sound absorption coefficients of micro-fiber fabrics by reverberation room method

The sound absorption properties of materials are important not only for noise reduction, but also for controlling reverberation time for speech intelligibility in rooms and for promoting fuller sound in concert halls. Industrial textiles are focusing on these materials' application for sound absorption, thus new textiles were to be examined in relation to this performance. Micro-fiber fabric has fine fibers and a high surface area and it ahs been used in such applications as wipers, thermal insulator, filters or breathsble layers. It can be also used for sound absorption. This paper examines the possibility of using micro-fiber fabrics as sound absorbent materials. We tested the sound absorption coefficients of five micro-fiber fabrics and one regular fiber fabric by the reverberation room method. The results showed that the micro-fiber fabrics sound absorption is superior to that of conventional fabric with the same thickness or weight, and the micro-fiber fabrics' structure was found to be important to controlling sound absorption according to sound frequency. Fabric density was found to have more effect than fabric thickness or weight on sound absorption, and the Noise Reduction Coefficient increases to its highest value at a fabric density of about 0.14 g/cm(3), and it decreases thereafter.