The acoustical design and modelling of a subwavelength hexagonal acoustic metamaterial for multipurpose use and potential building applications

The development and application of noise control strategies on subwavelength regimes have thus demanded a continuous effort by several researchers. In recent decades, the advent of acoustic metamaterials arose as a novel strategy on the sound wave manipulation and the development of subwavelength dimensions acoustic devices. In previous works by the authors, analytical approaches were developed to provide a more comprehensive acoustic characterization of the proposed metamaterial through equivalent fluid models. In contrast, the present work aims to advance the concept by introducing the design of a ventilated subwavelength acoustic metamaterial and by examining its potential applicability across multiple building-related contexts, including sound absorption and sound transmission control. By means of optimized geometrical configurations, it is possible to achieve quasi-perfect sound absorption (a > 0.8[-]) or enhanced sound transmission loss efficiency (> 30 [dB]) within subwavelength regimes. The results demonstrate that the proposed acoustic metamaterial operates effectively at subwavelength dimensions and within selectively tuned attenuation frequency bands, enabling single-, dual-, triple-, or hexa-resonance configurations. These features introduce additional degrees of freedom into the overall design concept, offering promising applications across various engineering fields, particularly in building acoustics.

Keywords: acoustic metamaterial, association of Helmholtz resonators, sound absorption, sound transmission loss, building acoustics

Denilson Ramos, Francesco Pompoli, Luís Godinho, Paulo Amado-Mendes, Paulo Mareze, The acoustical design and modelling of a subwavelength hexagonal acoustic metamaterial for multipurpose use and potential building applications in "RIVISTA ITALIANA DI ACUSTICA" Online First/2026, pp 1-14, DOI: 10.3280/ria2026oa22128