A Comprehensive Review on Noise Reducing Materials for Habitable Spaces

Millions of people are subjected to stress, particularly hearing losses due to the adverse impact of noise pollution. Noise mitigation demands inexpensive, efficient and feasible solutions to be developed in habitable spaces including long duration transport systems. The comprehensive review presented here focuses on different noise reducing materials being utilized presently, including recent developmental efforts towards noise mitigation. Sound absorption characterization and associated material parameters are presented initially. The material parameters affecting sound absorption are listed and defined subsequently. A summary about the foaming agents being widely utilized is presented next. The different materials like foams (open and closed cell), metamaterials, sandwiches, and microperforated panels are reviewed in detail before introducing the simulation studies of acoustic wave propagation in cellular structures. The applications are summarized before possible future trends and challenges in developing advanced smart, sustainable noise mitigating material.