“[S]peaking more clearly and slowly, reducing background noise and distractions, making sure the listener can see the speaker's face, and providing ample contextual information, may [also] help to improve the [] speech understanding [of voice recognition software].”
Yet, none of these elaborate software ever try to “see the speaker’s face.”  Why not, if it can improve their accuracy?
More pertinently, here is something that can help with the onset of Alzheimer’s: Reading out loud! That’s right, this simply task we did in grade school can help us now at our advanced age. So read out loud every chance you get, to your grandkids, your spouse or to yourself. It’s worth the effort.