Absorption of low-frequency noise using cavity bricks
DOI:
https://doi.org/10.55753/aev.v5e08.71Keywords:
sound absorption, low frequency, Helmholtz, resonatorsAbstract
This paper presents a study on the efficiency of concrete blocks as acoustic absorbers, transformed into resonators by adding a slit. Measurements were performed to determine the absorption coefficient of these resonators, both acting alone and coupled, at different resonance frequencies. The results showed that the porosity of the concrete block material significantly influences the resonator efficiency, and eliminating this porosity by painting reduced the efficiency by 20%. Furthermore, it was observed that the distance between the holes of the coupled resonators did not have a significant effect on the coupling of the resonators. Finally, the study concludes that the high porosity of the walls constituting the resonator enables coupling between the cavities of the concrete block, which may compromise the efficiency of the resonator assembly in a real situation of use.
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