Application of the International Standards for noise insulation assessment of a metamaterial-based ventilated window

In recent years, acoustic metamaterials (AMMs) have been developed to create more ergonomic designs that can be integrated into the built environment. For instance, embedding metamaterials in windows has facilitated effective ventilation and sound insulation. Presently, European standards provide specific guidelines for evaluating the insulation properties of façades, enabling the characterisation of both active and passive noise management solutions to ensure a healthy indoor environment. However, these standards primarily focus on closed partitions, limiting their applicability to noise management open systems. This study employs the ISO 10140 measurement method to assess a vertical metamaterial-based partition, namely an acoustic metawindow (AMW) unit, that, when open, allows noise insulation and ventilation contemporarily. The standardised level difference (Dn,e) is used to assess the performance of the open AMW unit's noise insulation. The results demonstrate the applicability of ISO 10140 for assessing an open AMW unit's performance, showcasing a Dn,e,w = 27 dB in the frequency range 1000-5000 Hz and an improvement over an open standard window ranging from 3 to 15 dB. This initial exploration could pave the way for more inclusive regulations considering ventilated sound-insulating devices as vertical partitions in the built environment and more comprehensive assessment methods for AMMs-based ventilated systems.