有确凿证据表明当时的表演者们戴着装有小型扩音器的面具，以辅助声音的方向性传播。
There is strong evidence that the actors wore masks that were fitted out with small megaphones to assist in increasing the directivity of the voices.
布莱克博士与戴维斯都承认他们本人各有两台手机，但在耳机与扩音器的使用上相当慎重，并只在信号良好的的地方打电话。
Both Dr. Black and Davis admitted that they still own two cell phones each, but are careful to use a headset or speakerphone, and only make calls in areas with good reception.
我清楚地听到扩音器在呼叫由华盛顿飞往迈阿密的旅客。
I distinctly heard the loudspeaker calling passengers for the Washington-Miami flight.
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