为什么坐飞机时我们总感觉耳朵要爆炸了?

 　　Most of us are familiar with this phenomenon of travel: ear-popping usually happens during takeoffs and landings.

　　大多数坐过飞机的人都熟悉这样的现象：飞机起飞或落地时我们的耳朵会有胀胀的感觉。

　　Our ears pop because of the change in air pressure as the plane ascends¹ or descends². At higher altitudes air pressure is lower, even though the plane is pressurized.

　　我们的耳朵之所以会有这种感觉是因为在飞机起飞或降落的时候发生的气压变化。在较高海拔区域气压较低，尽管飞机已经在加压了。

　　Our ears are sealed off inside our heads, so as the plane ascends or descends the pressure outside and inside our ears is different. This difference in pressure can distort our ear drums and be painful.

　　我们的耳朵在头内处于封闭状态，因此随着飞机上升或下降，耳朵内外的气压不同，而这种差异会扭曲我们的耳鼓并导致疼痛。

　　What needs to be done here is to equalize the pressure between our ears and the airplane cabin.

　　此时我们需要做的就是平衡耳朵和飞机机舱内的压力。

　　为什么坐飞机时我们总感觉耳朵要爆炸了?

　　Nature has provided the means for this with a tube that runs from the middle ear to the nasopharynx—the open area behind our noses. It's called the Eustachian tube.

　　刚好我们天生自带这种功能，由中耳延伸出的一条直达鼻的咽管道器官（在我们鼻子后面的一块开放区域）称为耳咽管。

　　Normally the Eustachian tube is closed, so in order to equalize the pressure we need to open it.

　　通常情况下耳咽管都是关闭的，但当我们需要平衡气压时我们需要打开它。

　　Seasoned travelers know that you can avoid the discomfort³ by swallowing or chewing gum when you feel the pressure change.

　　经验丰富的人知道，如果感到气压变化了，他们会通过吞咽或咀嚼口香糖来排除不适。

　　The mechanical action when we chew gum or swallow opens the Eustachian tube, and allows the pressure to be equalized. The opening of the Eustachian tube is associated with the “pop” we hear.

　　嚼口香糖或吞咽这些机械动作会帮助我们打开耳咽管，随即平衡气压，打开耳咽管的同时我们也会听到“嘭”的一声。

　　Incidentally, babies often cry on takeoff and landing because they don't know to chew or swallow. Having them suck on something can open their Eustachian tubes and alleviate⁴ the pain on their ears.

　　通常婴儿在起飞及降落时会哭是因为他们不知道来咀嚼咀嚼或吞咽。这时让他们吮吸点什么东西能够帮助他们打开耳咽管并缓解耳内的疼痛。

1 ascends   

v.上升，攀登( ascend的第三人称单数 )

参考例句：

• The azygos vein ascends in the right paravertebral gutter. 奇静脉在右侧脊柱旁沟内上升。 来自辞典例句
• The mortality curve ascends gradually to a plateau at age 65. 死亡曲线逐渐上升，到65岁时成平稳状态。 来自辞典例句

2 descends   

v.下来( descend的第三人称单数 )；下去；下降；下斜

参考例句：

• This festival descends from a religious rite. 这个节日起源于宗教仪式。 来自《简明英汉词典》
• The path descends steeply to the village. 小路陡直而下直到村子。 来自《简明英汉词典》

3 discomfort   

n.不舒服，不安，难过，困难，不方便

参考例句：

• One has to bear a little discomfort while travelling.旅行中总要忍受一点不便。
• She turned red with discomfort when the teacher spoke.老师讲话时她不好意思地红着脸。

4 alleviate   

v.减轻，缓和，缓解(痛苦等)

参考例句：

• The doctor gave her an injection to alleviate the pain.医生给她注射以减轻疼痛。
• Nothing could alleviate his distress.什么都不能减轻他的痛苦。