Sometimes the eustachian tube may malfunction .

有时候，咽鼓管会功能失调。

Bacteria or viruses that have entered the middle ear through the eustachian tube also can get trapped in this way .

通过咽鼓管进入中耳的细菌或病毒同样也会以这种方式陷入。

Their eustachian tubes are shorter and more horizontal than those of adults which allows bacteria and viruses to find their way into the middle ear more easily .

他们的咽鼓管比成人的要短、更平一些，这就使得细菌和病毒更容易找到通往中耳的路。

This is taken care of by the eustachian tube a small passage that connects the middle ear to the back of the throat behind the nose .

这是由咽鼓管负责的，这是一个小通道，将中耳和鼻子后面喉咙后部相连接。

For example when someone has a cold or an allergy affecting the nasal passages the eustachian tube may become blocked by congestion in its lining or by mucus within the tube .

比如说，当有人感冒或者鼻腔过敏的时候，咽鼓管可能会被其内层充血或者管内的黏液阻塞。