Good points all, and I'm glad this threat was resurrected because I'm pretty passionate about this...
There are so many variables to consider. What type of course is it? If I'm building a course about how to write Arabic script for a non-Arabic speaker I might decide to have audio and animation of the script being written playing simultaneously ("Aaaslam Ali-koom" as the script is drawn out from right-to-left, maybe along with the English equivalent). However, if I'm building a course about how to change timing belts in Volvos (bear with me, not a car guy here) instead of:
Audio: The timing belt is located under the flux capacitor in the '78 Volvo
On-Screen Text: The timing belt is located under the flux capacitor in the '78 Volvo
On-Screen Animation: Timing Belt is circled/highlighted in a graphic/picture of a '78 Volvo engine
I might go with:
Audio: The timing belt is located under the flux capacitor in the '78 Volvo
On-Screen Text: "Flux Capacitor" and "Timing Belt" (timed to coincide with audio)
On-Screen Animation: Timing Belt is circled/highlighted (and maybe the flux capacitor too) in a graphic/picture of a '78 Volvo engine (or better yet, a 3D representation of the engine - boom!)
But yeah, generally in e-Learning having the audio, on-screen text, and transcript/notes tab have the exact same content is going to be a design flaw in my humble experience/opinion.