3D Labyrinthine-type acoustical metamaterial proposals for sound control in architectural applications

The purpose of this research is to develop alternative 3D labyrinthine-type acoustical metamaterials by utilizing 'space-coiling' for sound control in architectural applications. Acoustical metamaterials have a great potential on their application for building and room acoustics due to their extreme properties in sound absorption and transmission. They can be used as an interior partition, an interior surface layer, and also as a design element. They are advantageous in comparison to the traditional acoustical materials such that by tuning their physical properties more hygienic, lighter or thinner alternatives can be produced. In this research, the design ideas of acoustic metamaterials (AMMs) originate from golden ratio (GR) and web labyrinth (WL). In data collection and analysis, both experimental and theoretical methods are used. As a first step, all design alternatives are modelled in 3D, then are printed out by a CNC 3D printer, finally, the AMMs are tested in impedance tube to observe their acoustical properties. Initial results indicate that WL shows good performance in terms of transmission loss and GR has efficiency for sound absorption in low frequency range. Both options are better than Solid sample. The results indicate the potential of designed alternatives and are supportive for future optimization.