There are times when no matter how effective our communication skills are there are mis communications. And although we listen to information that is transmitted to us for internalization and understanding, we gather most of the information from the physical signals. Such signals include body language, facial gestures ones distance from us etc. Also in conjunction to the language used to communicate we seem to translate the pitch and tone before the words.
One barrier to effective communication skills can be obviously language. The choice of words and language will influence how the listener receives the communication. Since language is a symbolic representation that is learned by those involved in the interaction of communication, room is left open for misinterpretation and distortion of the information being sent. This is due to one's own concept of what the symbolism of a particular word or language represents and the fact that the interpretation may vary from person to person.
Another problem that can prevent effective communication skills is body language. There are many times when what comes out of our mouth does not match our physical gestures and body language. In this case the person receiving information fluctuates between the words being said and the visuals to come to a conclusion about what information is being transmitted to them. This creates mixed signals for the receiver, which makes them distrust the information being given to them.
The biggest factor in nonverbal body language is the face. We all look at people's faces for signs when they are communicating with us. We look to see if they are speaking the truth or lying to us. Similarly posture effects our interpretation of information as well. One's posture can come across as aggressive, shy, indifferent etc. in a communication interaction affecting how we think about the information we are receiving.
Another thing to consider for effective communication skills is ones tone and pitch. We can use a particular word and with the incorrect tone or pitch the meaning of the word is altered. Ex. If we yell at someone with an angry face "I'm Happy Today!!!" They will look at the person's way of saying the words as being an angry person today not happy. Think about how many ways a word can be said and even though it is the same word, the meanings change with the context with which it is used. This is the same for tone and pitch. This is where the phrase "Its not what you say, it's how you say it" is illustrated.
People who know how to use effective communication skills know the importance of non-verbal communication as well. They know that just as important as what we say it is how we say it. They know the best way to convey messages is with body language and tone/pitch that reinforces what they are trying to convey. This leaves little room for misinterpretations on the part of the listener.