Our eldest DS would often read / do homework while a teacher was lecturing. That often didn't go over well with the teacher as they assumed you can't do two things at once and doing anything else while they're lecturing was rude and disrespectful. At one point DS said he'd heard everything the teacher said which the teacher said was impossible.....until the teacher quizzed DS who responded accurately to each question. The teacher just fumed.
I guess my message here is, while we've seen the ability to focus well enough on multiple conversations or tasks at the same time, it's probably a good idea to teach our children that it's generally not well received to do so, especially with authority figures.
