Deep sub-wavelength acoustic transmission enhancement and whisper via the monopole resonance in meta-cavities. (28th February 2023)

• Record Type: Journal Article
• Authors: Lei, Yunzhong; Hui Wu, Jiu; Wang, Libo; Huang, Yao; Niu, Jiamin
• Is Part Of: Applied acoustics. Volume 203(2023)
• Publication Date: 2023-02-28
• Subjects: Acoustic emission and reception enhancement -- Monopole resonance -- Private acoustic transmission; Acoustical engineering -- Periodicals; Periodicals; 620.2
• DOI: 10.1016/j.apacoust.2023.109227
• Languages: English
• ISSNs: 0003-682X

Abstract

Highlights: A system of two meta -cavities composed consisting of a central cavity, four straight channels and eight side cavities is proposed. Acoustic emission and reception enhancement can be achieved through monopole resonance, respectively. The acoustic signal detected using the system with the meta -cavity radius of 30 mm (0.07λ) is enhanced by 36 dB. While ensuring the same reception, the ambient sound pressure level by 20 dB to achieve whispering. Abstract: In this paper, a system consisting of two identical meta -cavities that can generate Mie resonances is proposed, aiming to achieve efficient acoustic transmission enhancement and whisper in the deep sub-wavelength range. Unlike traditional Mie resonators with zigzag channels, the meta -cavity comprises a central cavity, four straight channels, and eight interconnected side branch cavities. By placing a monopole source in the center or outside of the meta -cavity, acoustic emission and reception enhancement can be achieved through monopole resonance, respectively. Considering thermo-viscous loss, The simulation and experimental results show that the acoustic signal detected using the system with the meta -cavity radius of 30 mm (0.07λ) is enhanced by 36 dB. While ensuring the same reception, it can reduce the ambient sound pressure level (SPL) by 20 dB to achieve whispering. The system is expected to show significant potential in practical applications based on the results.