It does this by fitting small piezoelectric acoustic sensors to parts of the structure to detect the particular frequency of noise caused by a crack in aircraft-grade aluminium.

把小型压电声传感器安装到这种构造部位上，检测由航空级铝材裂纹所致的特定频率的噪音，靠这样就能监测飞机裂纹。

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The GPS IIF team completed a series of acoustic tests that replicate the noise levels expected during the spacecraft's launch into orbit.

GPS IIF团队完成了一系列声音测试，复制了太空船进入轨道预计将产生的噪音水平。

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The Nautilus meets withstands shock, vibration, salt, fog, drip, fungus, acoustic noise, and EMI.

鹦鹉螺还能抵抗撞击、振动、防盐防雾、防渗水并能经受噪声和电磁干扰的影响。

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And this design reduced feedback, a noise problem common with acoustic guitars.

VOA: special.2009.09.27

The lower shear forces and more efficient thermal conduction of helium also mean the drive will run cooler and will emit less acoustic noise.

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This makes it easier to scale up the number of disks in the drive while keeping drive power consumption and acoustic noise at acceptable levels (and even lower than the air filled drives).

FORBES: Rare Gases and Fine Lines

Slow-retention foam is used in the ear pads to create a comfortable fit that also improves passive noise cancellation by creating an acoustic seal.

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