When it is struck, a tuning fork produces an almost pure tone, retaining its pitch over a long period of time.

音叉被敲击时，产生几乎纯质的音调，其音量经久不衰。

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Musicians had no advantage when it came to pure tone thresholds.

当涉及纯音阈值时音乐家没有优势。

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Scientists asked participants to detect the onset or disappearance of different pure-tone sounds within soundscapes of ranging complexity.

科学家们要求被试者探测复杂性在一定范围内的音景中不同纯音的出现和消失。

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Music critics say Jason Mraz sings with a pure and clear tone on the song "Make it Mine."

VOA: special.2010.01.29

More direct evidence from studies of experiments with animals and humans, however, suggests that we may have to alter the very concept of what we mean by hearing loss, and that current tests - particularly pure-tone audiometry which measures our ability to perform "pin-drop" hearing - may not be sufficient to pick up the early signs of a decline in hearing function.

BBC: Viewpoint: Does deafness contribute to dementia?