Oh, I can definitely do what you're describing, aquinas-- but NOT what EN is describing, not at all.
That is, for me,
speaking is on a different "track" than listening. I don't really
hear my own speaking,
per se, so much as script it internally before engaging the mouth, if that makes sense.
So it's no problem to release the brake and listen at the same time.
It all goes into the same transcript. Complete conversation in my head-- no problem.
I can do the same thing with auditory information in, say, a large group of people-- be following script entries from a variety of persons at once, that is.
With numbers, though, or a delay-- egads. Never.