Changes in government policy in Australia mean that accessibility is a priority. Developing lots of online material with videos, this means I'm spending a lot of my time producing closed captions! Almost sick of the sound of my own voice.
I've been using the captions option on YouTube. Sometimes the automatic captions are worth editing, but often times it is easier to start from scratch. If you've recorded with a script you can cut and paste it straight into the video transcript window. Otherwise, the video play pauses while you are typing and has a 5 second rewind which is useful. You can then download the script file and reattach with software like Handbreak which is Freeware.
I think it is important, whether you are producing internal course material of stuff you want others to watch on YouTube to not exclude the hearing impaired. Once you've done it a few times it becomes just another part of the production process.