Acoustical Materials from Conventional to Cutting-Edge Innovations─An Overview

Abstract With rapid urbanization and industrial expansion, noise pollution has escalated into a pervasive environmental and public health crisis. Thus, an imperative need arises for both advanced sound mitigation strategies and, especially, a fundamental shift toward sustainability to meet pressing worldwide environmental policies. The overview critically examines, unlike the already published reviews, the broad spectrum of AMs─from established conventional options to cutting-edge innovations─while consistently evaluating them through the lenses of working mechanisms, acoustic performance, and holistic sustainability (including manufacturing and life-cycle considerations). For applications where blocking airborne sound is the primary objective, natural materials with higher density and mass, such as denser types of wood or composites incorporating mass-enhancing components, should be prioritized because the acoustical properties of natural materials as soundproofing materials are influenced by a complex interplay of factors (density, mass, porosity, air permeability, thickness, internal structure, resonant frequencies, surface area, and texture). This paper systematically explores the fundamental principles of sound interaction with materials, classifying traditional, natural, hybrid, and emerging smart materials and metamaterials. The following discussion explores key performance metrics, practical applications, and the inherent challenges and future directions in the field, striving to offer a holistic perspective on the ongoing quest for effective, durable, and truly sustainable acoustic solutions. Therefore, this overview is intended to be an exhaustive, comprehensive, and valuable tool for engineers and researchers in the field of acoustic materials, with real help for saving cost and time throughout the design process. Such an overview covering all acoustic material types with elements of sustainability and future perspectives has never been reported before.