While recently attending a holiday party, one of the questions that provoked a great of interaction dealt with the subject of communication and why we have so much difficulty having others understand us and why others can be so difficult to understand.
There probably as many different reasons for these difficulties as there are people.  Some are as basic as facing the reality that some individuals do not want to understand others.  Some have their own needs met by not being understandable by others.
If we accept the complexity of humans, then it is easy to see that there can be many complex and diverse reasons for humans to struggle to communicate effectively with each other.    After all, this continual struggle is one reason why Dr. Phil is popular and many psychologists have employment.
One idea that I often used in some of my classes was the comparison of human communication channels with those of radio and television.  
For example, at any time of the day and night the air is full of radio and television waves carrying all types of sound.   Unless we find a successful way to “tune in” to these waves, all we hear is silence. Broadcasting is a 24-hour operation.  Just because we cannot hear the sounds being broadcast, it does not mean that nothing is available. 
As a human being, we must decide that we want to hear from another.  Many do not hear because they individually make the choice not to talk or listen.
If we decide we want to communicate, then we are faced with finding the correct tools/receivers for communicating.  Just having a tool does not guarantee that we will be successful in our efforts to communicate.  We may have a radio, but it will not bring in television signals.  A person may know how to listen, but there is no guarantee that they will chose to do so.
Even after we find the same tool as the other person, we then struggle to find the same channel.   As was happening at the aforementioned party, there were plenty of people talking, but few were on the same channel as the other person, so few were being heard.  
We each have our own favorite channels in communicating, so we automatically use them and not bother to find what channel another is using.  There is lots of noise in our world, but, just like the silent radio/television waves, we do not understand this noise until we use the correct channel.
If one wants to hear classical music, they would not select a channel that broadcasts political talk.  If we want to learn, we could choose a give-and-talk channel versus a channel where there is argument and only one point of view offered.
We get to choose the channel(s) on which we want to send out our thoughts and feelings to others.   If we are wise, we give them plenty of cues on where this channel can be found and we broadcast what we commit to offer.  
If we want to listen, we can go to specific channel or ‘spin the dial’ until we find something of interest.  The key remains the same:  each of us needs to be on the same channel if we are to effectively communicate.
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