特别广播英语第 295 课：Why Can We Hear the Sound of the Ocean in a Shell?
贝壳传来海洋之音？-1

Most children have probably wondered at the noise of roaring ocean waves magically captured inside seashells held up to their ears. 大多数的孩子对从握在耳畔的贝壳里能听到神奇的海浪澎湃声啧啧称奇。

According to popular belief, anyone lucky enough to hold a big, spiral conch shell will be treated to the loudest rendition of one of nature's "recordings." 许多人深信，谁能幸运地捡到大海螺贝壳，便能受邀聆听大自然最盛大的“原音重现”。

A similar, but quieter effect can be heard by using an empty cup or even just by cupping a hand over an ear. 把一个空杯子或只是将手合成杯状贴近耳朵，就可以听到类似但比较小的声音效果。

One popular explanation is that the sound of blood rushing through the ear's blood vessels echoes inside the cup. 一个比较普遍的解释认为这是血液在耳朵血管里流动的声音在杯中回荡不已引起的效果。

This is unlikely, because the sound ought to be louder after vigorous exercise, yet it remains at the same level. 这说法是不可能的。因为照这样的解释，人在剧烈运动后听到的声音应该会更大，但事实上仍然维持相同的音量。

Air flowing through the shell or cup has also been suggested as a possible cause, but experiments in soundproof rooms have disproved this. 在贝壳或杯子里流动的空气，也被认为是产生声音的可能因素之一，然而在隔音的房间里所做的实验已将这个可能推翻。

No sound comes from the shell, though there is plenty of air in the room. 虽然隔音房内有充足的空气，贝壳里却一片安静。

In fact, the answer is fairly simple, and can be summed up in two words: ambient noise. 事实上，问题的答案非常简单，简单到可以用两个字来概括：周围的杂音。