Think of the absent minded professor or the pensive poet. Both may have thought processes that personality profilers such as Emergentics might classify as analytical or competing, meaning that they have the capacity to take in massive amounts of information and digest it to a reasonable conclusion. Until that point and during the "digestive" thinking process however, speakers may feel like they're talking to the wind.
So, ironically, sitting still and staring into a speaker's eyes does not make us better listeners. A lot of people even listen better if movement is involved.
(This is not to be confused with people who actually think they can listen - or drive - while texting. Some activities just don't help us perform better at listening or paying attention.)
In fact, there are a growing number of "movement and learning" advocates such as John Ratey, who is leading the charge and even espouses exercise as "medicine" for the brain, especially for different learners, such as those with ADHD. The idea is to get oxygen to the brain to keep it operating with vigor and to keep it's owner interested and focused. For example, Ratey talks about the "brain fog" that happens to most of us mid-day. That's not good for listening, learning or most anything else but napping.
Bottom line? Because we all listen and learn differently, we all engage differently too. Most of us get that when it comes to speaking. It's also key when it comes to listening.
When incorporating two-way communications, whether in your organization or in your relationships, be open to various listening and learning styles if you want people to engage with the information you're offering. And consider the importance of movement, especially in your workplace. Sitting at a desk staring at a computer for hours is not productive or helpful when digesting onslaughts of communication like most people do these days - it's just the prelude to brain melt and diminishing returns.
Let the force be with you!