| CPC G10K 11/172 (2013.01) [G10K 11/162 (2013.01); G10K 11/36 (2013.01)] | 20 Claims |

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1. An acoustic metasurface structure comprising:
a main body having
a sound-absorbing hole formed at a surface of the main body; a ratio of a diameter of the main body to a diameter of the sound-absorbing hole being from 9.8:1 to 12.35:1;
an externally-connecting configuration formed inside the main body and having
an externally-connecting cavity; and
an externally-connecting tube disposed inside the externally-connecting cavity; two ends of the externally-connecting tube being open and in fluid communication with each other; one of the two ends of the externally-connecting tube connected to the sound-absorbing hole to communicate with an external environment; the other one of the two ends of the externally-connecting tube communicating with the externally-connecting cavity; and
an inner configuration formed inside the main body and having
an inner cavity; and
an inner tube disposed inside the inner cavity; two ends of the inner tube being open and in fluid communication with each other; the inner tube and the externally-connecting tube spaced apart from each other; one of the two ends of the inner tube communicating with the externally-connecting cavity of the externally-connecting configuration; the inner cavity communicating with the externally-connecting cavity through the inner tube.
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