[header] How to measure the effectiveness of communication [title] Hear the responses listeners give you. [step] If your audience (be it one person or many) tells you they don't understand what you are saying, hear them. Many a good point is lost on listeners when a speaker refuses to stop pressing on with their speech to clarify a point they've made. 
Stop and clarify what you are saying even if it means it'll take longer to make your point (s). [title] Don't take yourself, or your ideas, too seriously.