The hum of the spinning blades is the sound of China going green as it seeks to address the growing energy demands of its rapidly modernizing consumer society and fast-paced industrialization.

VOA: standard.2010.08.03

And perhaps the explanation has got to be the ubiquity of death is this kind of background, constant hum.

也许应该这么解释，死亡的无处不在,是一种背景的，持续的嗡嗡声。

耶鲁公开课 - 死亡课程节选

just in a sense that when she was taking, say, I don't know, class like C.C., which is Contemporary Civilization, or Lit. Hum.,

就好像她在上论当代文明，或人类文学这样的课程时，我不太清楚，

介绍好朋友 - SpeakingMax英语口语达人

We'll get to those, but we'll start with ordinary, everyday, hum-drum facts about us.

我们之后会讲到那些,但是我们将从我们自身常见的,日常事实讲起

耶鲁公开课 - 死亡课程节选

If you want to hum the piece quietly to yourself, that's fine; that's good.

如果你想自己跟着曲子,小声哼哼,没问题,那很好

耶鲁公开课 - 聆听音乐课程节选

If I hear lots of buzzing out there, that means you're into it, so hum the piece a little bit to yourself, Musorgsky's "Great Gate of Kiev" Here and Pictures at an Exhibition and see if you can write down those particular symbols.

如果我听到了很多嗡嗡声,就说明你们都投入进去了,那就自己跟着曲子小声哼哼吧,穆索尔斯基的《基辅的城门》,以及《图画展览会》,看看你是否可以写下那些特殊符号来

耶鲁公开课 - 聆听音乐课程节选