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1·Unless he was equipped with a directional microphone, he was out of earshot.

除非给他配备一个定向扬声器，否则谁也听不见他。《柯林斯英汉双解大词典》

2·The directional microphone trained on Foresters Cottage could pick up every word uttered inside at several hundred yards.

对准福雷斯特小屋的定向扩音器在几百码远的地方也能捕捉到里面的人所说的任何一句话。

3·The directional characteristic of microphone is an important factor in the measurement of directional distribution of sound field.

传声器的指向性对声场方向性分布的测量有很大影响。

4·This little clip-on omni-directional condenser microphone provides great sound at a reasonable cost.

这个小领夹式麦克风有很好的收音效果，值得这个价格。