If you are experiencing this issue while in Disney+ Try the following:
Play your program. The movie, show, etc. has to be playing for this to work.
Next press the star button on Roku remote.
Next, click on Accessibility & captions.
Next, click on Audio Track.
Next, use right arrow button to get to next screen to select language.
Next, scroll to an English setting (if that's the language you prefer). But look at the description above the word English. Be sure it does not include Audio Description. I selected the English setting that had (English, AAC, stereo)
You should notice that the voice description is now off.
Unfortunately, you have to do this every time you log into that app to play a movie.
Hope this helps.