Ten men and eight women entered the MRI scanner with noise-reducing headphones, with instructions to simply listen passively to the music.
十个男性和八个女性带着降噪耳机接受了mri扫描，并按照指示简单被动地接受音乐。
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NASA is exploring another noise-reducing technology - this one for helicopters - that is going through a process of discovery similar to that for the chevron.
One of the most recent noise-reducing technologies shepherded through the research process by NASA and now making a difference on commercial jet engines is chevrons.