Ultra-broadband sound reduction schemes covering living and working noise spectra are of high scientific and industrial significance. Here, we report, both theoretically and experimentally, on an ultra-broadband acoustic barrier assembled from space-coiling metamaterials (SCMs) supporting two Fano resonances. Moreover, acoustic hyper-damping is introduced by integrating additional thin viscous foam layers in the SCMs for optimizing the sound reduction performance. A simplified model is developed to study sound transmission behaviour of the SCMs under a normal incidence, which sets forth the basis to understand the working mechanism. An acoustic barrier with 220 mm thickness is then manufactured and tested to exhibit ultra-broadband transmission loss overall above 10 dB across the range 0.44–3.85 kHz, covering completely nine third-octave bands. In addition, unconventional broadband absorption in the dampened barrier (65%) is experimentally observed as well. We believe this work paves the way for realizing effective broadband sound insulation, absorption and sound wave controlling devices with efficient ventilation.

涵盖生活和工作噪声频谱的超宽带降噪方案具有很高的科学和工业意义。在这里，我们在理论上和实验上都报告了一种由支持两个Fano共振的空间盘绕超材料（SCM）组装而成的超宽带声屏障。此外，通过在SCM中集成其他薄的粘性泡沫层来引入声学超阻尼，以优化降噪性能。建立了一个简化模型来研究垂直入射下SCM的声音传播行为，为理解其工作机理奠定了基础。然后，制造并测试了厚度为220 mm的声屏障，在0.44–3.85 kHz的频率范围内，超宽带传输损耗总体上超过10 dB，完全覆盖了九个三倍频程频段。此外，还通过实验观察到在阻尼层中非常规的宽带吸收（65％）。我们相信这项工作为实现有效的宽带隔音，吸收和声波控制设备以及有效通风铺平了道路。