[Tempest1981]

Beyond the 2-minute intro video, the audio became very faint, with background noise like a fan humming. Made it tiring to listen to. (Does it get better later?)

[dmitriid]

If you’re on a Mac, it might be CoreAudio acting up.

Try sudo kill-ing coreaudiod

(disclaimer: I haven’t seen the video in question, but I had a similar problem with online videos in general)