What's wrong with closed captioning?

What's wrong with closed captioning?

Closed Captioning is a requirement for all educational videos used where I work at Blackhawk Technical College.  The belief is that Closed Captioning is the equivalent of watching and listening.  However, it is not.  It is watching and reading.  The first is a visual and audio channel, but the second is only a visual channel loaded up twice.  Closed Captioning requires the individual who is hearing impaired to split their attention between the graphics and the text; thereby making understanding more difficult and not less.  A better approach would be to utilize text annotations right on the screen.  These would be located on the screen where the action is taking place or the person is speaking.  That way the individual trying to learn from the video would not be have to divide their attention between the bottom of the screen where the Closed Captioning is taking place and the middle of the screen where the action is taking place.  The only thing you can be assured of with Closed Captioning is that the student will miss something.