Meta-silencer with designable timbre

Abstract Timbre, as one of the essential elements sound, plays an important role in determining sound properties, whereas its manipulation has been remaining challenging for passive mechanical systems due to intrinsic dispersion nature resonances. Here, we present a meta-silencer supporting intensive mode density well highly tunable loss and offering fresh pathway designable timbre broadband. Strong global coupling is induced by delicately modulated with guidance theoretical model, which efficiently suppresses resonance provides desirable frequency-selective wave-manipulation capacity tuning. As proof-of-concept demonstrations our design concepts, propose three meta-silencers designing targets high-efficiency broadband attenuation, efficiency-controlled attenuation timbre, respectively. The proposed all operate frequency range from 500 3200 Hz feature deep-subwavelength sizes around 50 mm. Our work opens up fundamental avenue manipulate resonances-controlled acoustic metamaterials may inspire development novel multifunctional devices noise-control engineering, impedance architectural acoustics.