He doesn't at first hear the horn fail to blow, and then later, when a truck pulls up behind him, he fails to hear a horn that does blow: He was looking at the sign, and he didn't hear the horn.

在一开始,是他没有注意到这点，到后来卡车停在身后时，他连响的喇叭都听不到了：,“他看着那个标牌，以至于没听到喇叭声。

耶鲁公开课 - 1945年后的美国小说课程节选

The horn obviously is a brass instrument and what makes the sound is a vibrating column of air.

显而易见的,圆号是个铜管乐器,它通过震动空气柱来发出声音

耶鲁公开课 - 聆听音乐课程节选

And then, of course, she gets a major clue for figuring out what the whole story is behind the Tristero and the post horn.

接下来，她自然得到了一个重要的线索,关于藏在Tristero，和驿车号之后的整个故事。

耶鲁公开课 - 1945年后的美国小说课程节选

They can push down the thirteenth partial and bring up the fifteenth and thereby change the sound of a clarinet into a French horn.

压低第十三分音,或者提高第十五分音,从而将单簧管的声音变成圆号的

耶鲁公开课 - 聆听音乐课程节选

In this case, the basic column of air is twelve and a half feet long and there are something called "Partials" or the "Harmonic series" That happens in anything, on a string instrument or whatever, but on the horn it's very distinct and that's what makes the different notes.

像这样,基本空气柱有十二个,每个半英尺长,圆号能发出分音,或泛音列,弦乐器或是,其他别的乐器中都有,但在圆号上,效果相当不同,这就是它能奏出不同音符的原因

耶鲁公开课 - 聆听音乐课程节选