https://www.selleckchem.com/pr....oducts/JNJ-7706621.h
This letter investigates an acoustic metamaterial exhibiting a unique sound pressure amplification mechanism for ultra-low frequency sound attenuation. The system is constructed by integrating a flexible panel into the side-branch duct of a Herschel-Quincke (HQ) tube. A new peak emerges in the Sound Transmission Loss (STL) at a frequency far lower than the frequencies of the HQ tube-induced STL peaks. It cannot, after careful comparisons, be attributed to any local resonances, including structural resonances of the flexible panel or