What the study reports
Four previously optimized unit-cell designs are assembled into one-dimensional and planar periodic structures. Numerical studies examine sound propagation along the periodicity and through the thickness. The authors also test through-thickness attenuation of a printed 2-by-2 prototype, reporting a 23.74 dB difference between centroid-based overall acoustic-pressure averages in their chirp measurement. Simulations and prototype measurements provide separate evidence levels. [1]
What this does not establish
The experiment is preliminary, uses a small specimen and includes room reflections. Numerical results depend on excitation and encapsulation conditions; the reported pressure reductions are not a universal transmission-loss rating. The authors state that the observed through-thickness attenuation still needs a physical explanation. Larger specimens and representative installation conditions require validation.
Our engineering reading
For acoustic product development, direction of incidence and surrounding domains deserve explicit treatment. The next useful step is a controlled transmission measurement on representative specimens and boundary conditions, rather than extrapolating the largest simulated reduction.
Editorial interpretation; not an additional measured result.Bandgap-Rich Unidimensional and Planar Periodic Metamaterials for Multi-Directional Acoustic Filtering
Applied Sciences · 29 September 2026
DOI: 10.3390/app16199654- Publisher version of record PRIMARY SOURCE · publisher · checked 3 October 2026
- Crossref bibliographic corroboration · metadata · checked 3 October 2026
Scientific coverage: Publisher full text and author metadata. Source check: 3 October 2026.
Metadata enrichment does not imply that the full scientific methods were reviewed.