在线英语听力室_免费在线英语听力学习网站

(单词翻译:双击或拖选)

In less you have a pair of noise-cancel headphones. Flying can be annoying to the ears. A lot of low-pitch rumbling¹ makes it into the cabin. The problem is ,the wings ,floors, ceilings ,and bolcats, are lined with the lightly material with a honey cone² structure, which adds to the structural³ integrity to the aircraft. But engine and airflow sound cuts right through. “The physical law says that the lighter⁴ the material is the worse it could block the sound.” UN? Jane is an acoustician in north Caroline University. In a quest for quiet, he and his colleagues constructed a similar material. But with a quarter mille-meter of thin latex, stretch across the cells of the honey cone. In test, the latext layer structure cut the intensity⁵ of low frequency rumbling to a thousand of its previous level. “enough” He says, ”to make an airplane cabin sound more like a peaceful living room. The study in the journal applied⁶ physics letters. Problem is the material Gin develops is six percent heavier than the standard stuff. And more weight means more fuel, means more expense. But if we settle for a little slightly quieter flight, Gin says could use less lay text. Making  the noise barking honey cone just a few percent heavier. Considering the honey cones⁷ are one of the lightest part of the airplane, you then looking at a modest plane weight gain. Of course, Let’s assume everyone wants a quieter plane. “Some people say that they actually want to hear the sound of engine. They don’t want that the cabin is too quiet. They want to make sure that the plane is flying. ” Sounds like  ? expensive  headphones a little while ?

点击收听单词发音