A decoupling-design strategy for high sound absorption in subwavelength structures with air ventilation.

A strategy based on the decoupling design of two elementary structures, both made of coiled-up channels, is proposed. One channeling structure is designed for blocking sound transmission, while the other element is used for absorbing sounds at low-transmission frequencies. Based on this strategy, the sound-absorbing sample with air ventilation is fabricated and its high-absorption capability is demonstrated experimentally. The expanding of sound absorption bandwidth by combining different absorptive channels into the sample structure is also demonstrated. The proposed method provides a new route towards broadband high sound absorption in ventilated structures.