55% of the meaning of spoken language is expressed through gestures and facial expressions – something we miss when the speaker and listener are not looking right at each other.
38% is through tone of voice, which is only heard when full attendance is on the speaker.
Only 7% of the meaning of the spoken word is expressed through the words themselves.
The average person speak about 125 words per minute but can process up to 500 words per minute, meaning that our attention is easily distracted by our thoughts (of various capacities), feelings, other internal noise, as well as the rest of the environment with other people, objects and events.
 Try saying the same phrase in a variety of voice tones; utilize different gestures and expressions, some which match the tone, others that do not. Do this in a small group, with a partner or in front of a mirror. Note the incongruities.
NOTE: Excellent activity for parents-to-be.