Closed Captions - How to create SRT files from existing MP3s?

To be ADA compliant, we need to find an expedient method to add CC to our existing courses.  We currently use Storyline 3.

First, there's the matter of exporting the existing audio.

In Storyline 3, I believe we'll need to individually export each voiceover file in many, many courses. (Weren't we able to export all audio at once with Articulate years ago??)

If we had Storyline 360, I know we could create TTS audio and check Generate Closed Captions.  For our existing human audio, I assume we would still need to export it from each slide, even with 360.

Next, we need to create SRT files for each audio file using 3rd party software. 

Finally, there's the chore of uploading the individual subtitle files to Storyline.

It would be great to find a tool that can bulk convert to SRT (and then have Storyline bulk upload the subtitles!)

Any thoughts on making this process less painful are appreciated. Thank you!