Here are some suggestions about the use of humor in speeches:
Never repeat a punch line. The mark of a clumsy joke teller is repetition of the punch line. It's like saying, ''I want to be sure you dumbbells got it, so I'm going to repeat it.''
When you use a laugh line, don't pause and wait for the audience to start laughing. That's begging. Instead, go right on. After the laughter starts—if it does—pause until it subsides.
Don't get flustered if your humor bombs. Professional comics have their own ways to recover after a joke falls flat. Unless you're a professional, you're better off to go on and ignore the bomb.
Never ad lib a joke. Don't tell one unless you have rehearsed it enough to have the pacing, timing, and punch ...