次声的

例句：

1. 1. The scientists detected the first sub-audible signals from space.
   科学家们探测到了来自太空的首次次声波信号。
2. 2. Infrasound waves have been shown to be effective in reducing stress levels.
   已经证明次声波能有效降低压力水平。
3. 3. The researchers believe that these sub-audible frequencies could be used for communication purposes.
   研究人员认为这些次声频率可能被用于通讯目的。