What does the 了 mean here? Is it pronounced le or Liao?
他清了清嗓子 = he cleared [his] throat
Here 了 is pronounced le (with neutral tone). The sentence itself comes at 2:52 in the video
As far as I understand, 了 here indicates that the action (clearing the throat) is completed. 清 is repeated to give the sense that the action was quick. I'll let someone with more knowledge on Chinese grammar to explain in more detail and correct me if I'm wrong