Everyone does it. What do they do? Nonverbal facial expressions communication.
As public speakers, it is necessary to master voluntary nonverbal facial expression communication. Much like gestures, this kind of communication ads the icing to the cake of your speech.
It is important to learn to read them in others, especially your audience. Since they are also part of our emotions, they are an involuntary reactions.
Also, based on the neuropsychology of self discipline, putting on a certain facial expression can result in attaining the emotion. For instance, by putting on a smile, even if you are feeling down, can ultimately lift your spirits. It may sound absurd but if you are feeling down and smile, you feel so stupid that your brain short circuits and you forget the reason you were feeling down.
Some expressions are considered almost universal. These may mean the same thing in many different cultures around the world.
The Big Picture of the Face
Until we can get photographs, become a student of facial expressions. Not in pictures but of live people. Stop talking and start listening to the nonverbal facial expression communication that they share with others.
You can do this at lunch. Do it in meetings. Start doing it where ever you can. Once you start to observe for the facial expressions, you will soon be able to start recognizing them when you are speaking from the platform.
Continue to master them and you will be able to pick out individual people in the audience who agree or disagree with what you are saying.
This is important when speaking to audiences. If the majority of an audience does not get the point, then you may have to add some further explanation. If you are boring the majority of the audience, then you may have to pick up the pace of your speech.
Here is a laundry list of facial expressions. Please copy it and start to check off the ones you recognize.
Nonverbal Facial Expressions Communication