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公开(公告)号:US20240185822A1
公开(公告)日:2024-06-06
申请号:US18287760
申请日:2022-04-21
Inventor: Ping SHENG , Ho Yiu MAK , Xiaonan ZHANG , Zhen DONG
IPC: G10K11/162 , B32B15/02 , G10K11/172
CPC classification number: G10K11/162 , B32B15/02 , G10K11/172
Abstract: The ultra-low frequency acoustic absorber (10) includes a hollow housing (12) having opposed first and second open ends (22, 24), and a plurality of metallic mesh layers (16) stacked within the housing (12). In order to secure the plurality of metallic mesh layers (16) within the hollow housing (12), first and second mesh covers (18, 20) may cover the first and second open ends (22, 24) of the hollow housing (12), respectively. At least one spacer (14) may be provided to form a gap between the housing (12) and a support surface, such as a hard wall (W) or the like. The at least one spacer (14) may have a length sufficient to space the ultra-low frequency acoustic absorber (10) at the position of optimal absorption based on an acoustic soft 10 boundary condition (ASBC).
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2.
公开(公告)号:US20200211527A1
公开(公告)日:2020-07-02
申请号:US16731376
申请日:2019-12-31
Inventor: Ping SHENG , Zhen DONG , Xiaonan ZHANG , Jie PAN , Ho Yiu MAK , Guancong MA
IPC: G10K11/178 , H04R1/40 , H04R3/12
Abstract: An active sound barrier has at least one passive sound absorber at or near a boundary location. A microphone provides an output to a frequency division module, in which a plural of frequencies are filtered to provide outputs corresponding to frequency segments of the receiving transducer output at respective ones of the frequencies. An active driving circuit drives plural speakers or output transducers at respective ones of the frequencies, with at least a subset of the speakers or output transducers at or close to the barrier. The speakers or output transducers cooperate with the passive sound absorber to reduce noise across a wide frequency band as well as to effect an electrically switchable soft boundary.
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