Acoustic configurations incorporating resonators with embedded extended necks have been widely studied for low-frequency broadband sound absorption. However, the large cavity volume required for low-frequency performance often conflicts with the mechanical load-bearing capacity of the structure, hindering practical implementation. To address this limitation, we propose an integrated acoustic absorption-mechanical metamaterial (AAMM) that synergistically combines efficient sound absorption with enhanced mechanical strength. Extending the embedded neck to the cavity bottom achieves a dual advantage: it raises the acoustic mass to preserve low-frequency absorption, while the neck itself acts as a structural reinforcement, improving load-bearing capacity. This design significantly enhances mechanical performance without sacrificing acoustic performance. Theoretical and numerical analyses show that introducing holes along the neck sidewalls and optimizing their size, position, and number enable the tailoring of acoustic impedance, providing greater design flexibility. To broaden the sound absorption bandwidth, a 42 mm-thick sound absorber composed of nine parallel-coupled units is developed, exhibiting effective sound absorption between 315 and 530 Hz. Mechanical compression tests demonstrate that, compared to conventional embedded extended neck resonators, the proposed AAMM exhibits a 249% increase in ultimate compressive strength, a 310% improvement in maximum energy absorption capacity, and significantly enhanced impact resistance. This design presents a dual-purpose material that successfully reconciles acoustic and mechanical requirements, further expanding the application scope of acoustic metamaterials in engineering practice.
MAO et al. (Wed,) studied this question.