But above and beyond its beauty, the hair bundle is an antenna.

但除去它的美丽不提，这个毛束是一根天线。

When the hair bundle is pushed in the opposite direction, the channels close.

当毛束被朝反方向推动时，离子通道就关上了。

When sound energy impinges upon the hair bundle, it pushes it in the direction towards its taller edge.

当声音能量冲击到毛束时，它会将毛束朝更高的一端推动。

So even at rest, in the absence of any input, an active hair bundle is constantly trembling.

即使在静息状态，没有任何输入信号的情况下，一根活跃的毛束也一直不停地在颤动。

A louder sound pushes the hair bundle farther, opens the channel longer, lets more ions in and gives rise to a bigger response.

更响的声音会把毛束推得更远，离子通道打开的时间更久，进入细胞的离子更多，反应也就更强。

At the top of each hair bundle, as you can see in this image, there's a fine filament connecting each of the little hairs, the stereocilia.

在这张图里能看到，在每一簇毛束的顶上，都有一根纤细的丝，把每根叫做静纤毛的小纤毛连接起来。

But above and beyond its beauty, the hair bundle is a machine for converting sound vibrations into electrical responses that the brain can then interpret.

但除了它的美丽之外，发束还是一台将声音振动转化为大脑可以解释的电反应的机器。

First of all, the active process amplifies sound, so you can hear, at threshold, sounds that move the hair bundle by a distance of only about three-tenths of a nanometer.

首先，有源放大过程能放大声音，因此你能听见的最小声音可以低到让毛束移动仅 0.3 纳米。

And we were just hearing from neuroscientist Jim Hudspeth describing the sensory receptors in our ears - hundreds of microscopic hair cells that make up the hair bundle.

我们刚刚听到神经科学家吉姆·哈德斯佩斯 (Jim Hudspeth) 描述了我们耳朵中的感觉受体——构成发束的数百个微小毛细胞。

And, most importantly, a back-and-forth motion of the hair bundle, as ensues during the application of acoustic waves, alternately opens and closes the channel, and each opening admits millions and millions of ions into the cell.

最重要的是，声波会让毛束前后来回运动，离子通道就会交替着打开、关闭，每次打开都会让数以百万的离子进入细胞。