Lattice metamaterials as advanced airborne sound insulators

. Airborne sound insulation is vital for noise reduction across various engineering fields. Traditional mass-based soundproofing methods, while effective, are often hindered by their bulkiness and limited ventilation capability. In contrast, lattice metamaterials provide a lightweight architected alternative with high tunability, enabling the use of periodic geometries to manipulate sound through mechanisms such as Bragg scattering and local resonance. This perspective explores the acoustic capabilities of various lattice morphologies, offers preliminary recommendations on geometry selection for effective sound insulation, and presents a generalized analytical model for predicting sound transmission loss. We also present a forward-looking discussion on the unbounded design potential of lattice topologies, highlighting opportunities for multifunctionality and outlining future directions in smart design, adaptive lattice structures, and data-driven optimization to enable advanced noise control and the development of multifunctional metamaterials.