This paper compiles the recent research findings on the Sound Absorption Coefficient (SAC), which is one of the most important factors in material performance in terms of acoustics. It reviews the effects of material properties, shape features, and optimization methods on SAC. SAC values of natural fibers, nonwoven fabrics, and composites are high, with the SAC performance influenced by thickness, density, and porosity. SAC prediction and optimization are improved by state-of-the-art techniques such as Response Surface Methodology and Artificial Neural Networks. Importantly, recycled materials have competitive SAC values, which is in sync with sustainable trends. The work also identifies various factors that influence SAC and opens possibilities for the creation of efficient and environmentally friendly acoustic systems. Further improvements of the existing predictive models are expected, as well as the analysis of the material performance in real-use conditions.
Žunjić et al. (Mon,) studied this question.