Noise pollution has become a significant global problem in recent years. Unfortunately,
conventional acoustic materials cannot offer substantial improvements in noise reduction …

Acoustic metamaterials, structured to produce anomalous reflection and refraction indices
that are not found in conventional materials, are gaining prominence in engineering …

Metamaterials are rationally designed man-made structures composed of functional building
blocks that are densely packed into an effective (crystalline) material. While metamaterials …

A hybrid acoustic metamaterial is proposed as a new class of sound absorber, which
exhibits superior broadband low-frequency sound absorption as well as excellent …

Initially proposed to achieve strong noise isolation levels beyond the mass-density law,
acoustic metamaterials (AMMs) have now overturned the conventional views in all aspects …

In this Letter, we theoretically propose and experimentally demonstrate a three-dimensional
soundproof acoustic cage structure, hereby denoted as an acoustic metacage. The …

Membrane-type acoustic metamaterials (MAM) are novel, lightweight and compact materials
that can be used to isolate the sound at low frequencies beyond the limits of conventional …

Low-frequency and broadband noise reductions have always been a major industrial
concern, as they pose a significant challenge. Although acoustic metamaterials are …

Sound absorption for a broad frequency range requires sound dissipation. The mechanics of
acoustic metamaterials for non-dissipative applications has been extensively studied, but …

This paper provides a review and fundamental physical interpretation for the effective
densities and moduli of acoustic metamaterials. We introduce the terminology of hidden …