Here is a screen grab of a recent video I uploaded to Youtube and asked them to generate a closed caption file for me.
The reasons for doing this are many.
For me it is great to be able to have my international students be able to read my text as I talk.
For you it may be the added SEO and student benefit of being able to post a transcript of what you have said.
Text that can be ranked by Google and read by students as well.
You can upload your video in private mode in case you want just want to have YouTube generate a standard caption for you.
After you upload your video, go to settings and click on the CC logo tab.
It is here that you can ask the dashboard to auto-generate a CC file for you.
I found that the voice recognition software did a pretty good job, and the tools lets you easily go in a edit your text to clean up any errors.
It really helps to have a great audio soundtrack with clear speaking, dictation and pacing.
Also avoid using a music backing track for your lectures and you should have similar results to mine.
Once you have your captions created, you can download them and have the text on hand for blog posts or cross-posting to platforms that support .srt or other standard CC transcript files.
Having your videos searchable by the audio content is a game-changer. It is in your best interest to have all of your hosted video content to include the text transcript and Google makes a once-cumbersome task easy.