Dear Mr. Hickey,
How would you address a group of senators, governors, police officers, etc.? Would it be generally like the plural of "sir" and "ma'am" -- "ladies and gentlemen," or "assembled guests" for instance? Or do I mention just the top ones?
-- Jim Sternberg
If you have a wide variety of officials the challenge is to figure out a natural place to stop mentioning them by name so you don't spend your time picking out certain people in the audience ... and end up overlooking others.
Here is the standard approach: The speaker will specifically acknowledge those on the podium then go on to acknowledge everyone else in a general way.
E.g., The President at the State of the Union Message is on the podium with just the Speaker of the House of Representatives and The Vice President ... so he begins his speech with those officials in precedence order:
Madame Speaker, Mr. Vice President, distinguished guests, and the American people.... etc
If no one is on the podium with you ... thank just the person who introduced you ... so if Thomas Smith is the Master of Ceremonies...
Mr. Smith, distinguished visitors, and ladies and gentlemen...
And when ending your speech, I got some excellent advice from Linda Reed, a PSOW Graduate in Eugene, Oregon. Linda achieved her Distinguished Toastmaster (DTM) from Toastmasters International a few years ago. She suggests, "To end a speech the speaker would make their final point which could be a summarization of their strongest points or a call to action. Then the speaker can turn and extend a hand to shake hands with the person who will resume the control of the lectern or simply step back from the lectern, but not leave the lectern until the next speaker is there."