The person trying to communicate something has to listen harder than the person they are trying to communicate to. - Alan Alda
When you listen, are you just waiting for them to stop so you can talk? Then how much are you really listening? As with two actors on stage, one does not say their lines, once the other's lines are completed. Rather, one speaks their lines in response to the content of what the other's actor's lines were.
I would actually rather say, "...the person they are trying to communicate WITH". I've said for a very long time that communication in discourse is a two way street. In considering talking with another from a foreign country where English is a second language to them, we would do well to understand that even to the person closest to us, there may be a very similar process going on.
We tend to communicate in generalizations that if examined leave much to be desired in the way of clarity and understanding. Some people, confidence types and politicians for example, abuse and make use of this known unknown.
The one imparting information in a communication has to communicate their intention (and information) as they wish it to be understood. Yet they also have to do so in such a way as to best impart that knowledge to the other (for them to assimilate it) in a way (in ways?) where that person is capable of understanding it. And understanding it as much as is possible. As long as they understand the majority of it, or enough of it, then the communication is typically considered successful. Not infrequently however, it is later found that was simply not the case.
Just as well, the one being communicated to needs to actively try to understand not just what is being imparted to them (simply listening), but they also need to try to understand what the person communicating them them is attempting to communicate. This can be done by viewing the information coming in on a variety of levels and encompassing various degrees of specificity and generalities. Some of this is done invisible without thinking. However not always and not with as good a degree of understanding as is frequently required.
The point being... in simply telling what you have to say to someone, in their simply listening what someone is saying to someone, in the one imparting what they understand in a baseline format where the information is wholly contained within the information, it disregards how another is able to decode and associate that information in such a way that they are not only getting the baselines information, but also the intent and scope of what the person is trying to share.
Sounds like an overly complicated way of expressing a very simple concept.
Yet, in observing people's communication and listening skills, and at times the result of that communication, it is in no way simple. Otherwise we wouldn't have so many misunderstandings where so much of the time even in discourse where it is "understood" that it was understood by both, it frequently is not in both reflection and examination.
So. Go communicate. :)