Use YouTube to Add Subtitles to Narrated PowerPoint Lectures

A few years ago I narrated PowerPoint lectures for my hybrid microbiology course in which students take the lecture portion of the course online. I used Camtasia for Mac to narrate all of the lectures. I really like that software, and TechSmith’s technical support is great.

To make those narrated lectures accessible, I now must add subtitles. Unfortunately, Camtasia for Mac does not have speech to text capability. So I purchased an inexpensive PC laptop and have been using Camtasia for PC to add subtitles. As with any auto-generated subtitles it’s necessary to edit them, adding punctuation and correcting any mistakes. For instance, when I said, “Endospore,” the subtitle the program added would be, “and of course”. Camtasia lets you add words to a dictionary, and it was learning, understanding me better and better with each use. Had I had good equipment, I would have had far fewer problems. With that inexpensive laptop and no external keyboard, though, it was taking me two to three hours to finish a 15 minute presentation.

We are not permitted to upload any inaccessible materials to the college’s CMS. Since it has been taking so long to complete one lecture, I’m only about a chapter ahead of my students this semester. So any spare time that I have had has been devoted to adding subtitles. You can imagine my utter frustration one day as I checked a file I knew I had completed only to find that it had no subtitles. I don’t know what I did wrong, but I absolutely could not believe that I lost all those hours of work.

I thought about throwing the PC laptop out the window. Instead, I went back into Camtasia, had it export the original file to YouTube, and let YouTube add the subtitles. Now, automatically adding subtitles alone wouldn’t be that impressive. What has astounded me is how accurate the subtitles are despite the scientific language in the presentations. And because I can use my Mac to edit, the time to complete a 15 minute presentation has been reduced to about 30 minutes. That’s a huge time-saver.

I’ve discovered that as long as the presentations are about 20 minutes or less, YouTube will automatically add subtitles. I haven’t figured out the exact limit yet, but YouTube did not add subtitles to a lecture that was just over 25 minutes. No problem. In Camtasia it’s easy to split that large file into two smaller ones.

Back to editing subtitles now…



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