Acoustic metaslit for regional sound insulation for a three-dimensional diffuse sound field incidence

An acoustic metaslit model designed for regional sound insulation, employing waveguide modes and the directivity of openings, is introduced. This model characterizes the frequency responses of numerical simulations. The performance of metaslits, made from steel plates, is experimentally validated under diffuse sound field conditions and assessed by measuring acoustic power differences using intensity probes. The frequency response of single and multiple-unit metaslits shows peaks at multiples of the target frequencies. Additionally, experimental results demonstrate that the three-dimensional structure does not influence the two-dimensional regional sound insulation phenomenon. Furthermore, comparisons between experimental and numerical results indicate that obstacles near the outlets of metaslits can impact their performance. • We propose a metaslit preventing incident waves from transmitting to a specific area from any angle. • We developed our model by analyzing two-dimensional waveguide modes and assessing the directivity at the opening. • Numerical results show that the metasurfaces achieve substantial sound insulation at the target frequency. • Experimentally, the metaslit demonstrated sound insulation in a three-dimensional diffuse sound field incidence. • Obstacle reflections within the target area reduce the metaslit's effectiveness.