Study on low frequency sound insulation characteristic of thin acoustic black hole

We use numerical and experimental methods to investigate the low frequency sound insulation characteristic of designed thin acoustic black hole (ABH). The numerical results show that the sound energy focusing effect plays a leading role in low frequency sound insulation of designed ABH, and the reflection at the edge of ABH is the main reason of sound insulation in medium and high frequencies. Experimental results display that the Sound Transmission Loss (STL) of the designed ABH is higher than 30 dB below 700 Hz, which shows that the isolated acoustic waves are more than 95%. The low frequency sound insulation performance of proposed ABHs is much better than the traditional acoustic materials, which has great potential applications for low frequency sound insulation.