Improvement of Low Frequency Sound Absorption in a Room

Low-frequency noise (LFN) poses significant challenges in noise control due to its long wavelengths and ability to penetrate barriers. This study introduces a novel metamaterial-based absorber optimized for low-frequency sound attenuation using a multicoiled structure. The theoretical foundation is established through an equivalent electrical-acoustic circuit representation, leading to the development of an impedance-matching design. The metamaterial’s performance is validated using Finite Element Analysis (FEA) simulations incorporating thermoviscous acoustic interactions and experiments. The results demonstrate high absorption efficiency at 50 Hz, with a total structure thickness of only 13 mm. A case study on an open duct system confirms that incorporating multiple absorption modules enhances noise reduction, with up to 21 dB attenuation observed. These findings highlight the effectiveness of the proposed metamaterial for compact and efficient low-frequency noise control applications.