Addressing the challenge of attenuating low-frequency broadband noise emerges as a critical concern within the fields of aeronautics, ground transportation, as well as construction industries. Over the last few decades, the literature has seen an increase in low-frequency noise control solutions centered around acoustic metamaterial designs. These proposed technologies exhibit promising acoustic performance, especially proving superior to conventional sound insulation materials in constrained spaces, such as in aerospace applications. Despite the efficacy of typical metamaterials in attenuating tonal noise through narrow resonant frequency maxima, practical applications reveal some challenges, as even slight variations in tonal noise frequencies can compromise the overall effectiveness of such solutions. In response to this, the present paper introduces a novel thin acoustic metamaterial design aimed at improving broadband noise attenuation at low frequencies. This design features an assembly of structured metamaterials arranged in series and in parallel and embedded within a layer of fiberglass. To assess the performance of this metamaterial in the low frequency domain, COMSOL Multiphysics were employed to predict the normal incidence sound absorption coefficient and the sound transmission loss of the structured acoustic material assembly. Results affirm the effectiveness of the proposed metamaterial design in reducing low-frequency noise across a wideband.

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