Vibro-acoustic metamaterials for increased STL in acoustic resonance driven environments

The last decade vibro-acoustic metamaterials have been heavily investigated due to their superior noise and vibration insulation properties, be it at least in some targeted and tuneable frequency ranges, referred to as stopbands or bandgaps. Resonant based vibroacoustic metamaterials allow to achieve pronounced acoustic insertion loss through the addition of a, often periodic, grid of resonant structures to a host material or structure. This results in frequency ranges for which free wave propagation is not possible in the host structure, and hence sound is not transmitted through that structure. In previous work of the authors, it was shown that it is possible to use this concept to achieve light and compact low frequency sound insulation, albeit in a laboratory environment. This paper discusses the potential of this solution in an environment characterized by resonance driven acoustic behaviour. Both numerically as experimentally it is shown that this concept can be used to suppress excitation of acoustic modes in an acoustic cavity due to acoustic sources outside of the cavity.