An accident, I was watching the tubing when the foreigner news caption put a beat slower than the video. He could finish the sentence caption to appear, look down so I personally feel can exercise the hearing, rather than stare at the subtitles, It is a good way to learn English.
I would like to set the subtitle on youtube, but there is no such function.
So I think we can find a subtitle player to control its own playback speed, as long as the belated can be.
On another great github I found a treasure trove of this software penguin subtitle player, English is really important, otherwise you can not find something important.
https://github.com/carsonip/Penguin-Subtitle-Player
Find this software, then just do the subtitles on youtube,
Then I found Download Youtube Subtitle's Grease Monkey scripts on github
https://github.com/1c7/Youtube-Auto-Subtitle-Download
That's it, you can see it!