I must agree with Susan on announcing dance names. My own technique is 
to announce them after the walkthrough and before the music starts. 
"come back to place and we'll dance ____ by ____". The beginners won't 
think that they're being left out because they all have been taught the 
dance, and in fact may be distracted by everyone starting to back up. 
The ones who are interested and have attention to spare will hear. This 
also lets the band know that we're ready for some music.
There are many ways for a caller to gain the attention of the dancers. 
Scarcity of speech is one of them, but tone of voice and force of 
personality do a lot more to making the evening fun. If just your tone 
and style of speech can convey "I'm having fun, please join me" and 
command attention and obedience as well, it really makes the evening fun 
for the dancers. It's not easy, especially for someone like me who tends 
to be shy, but it can be cultivated without sounding phony.
Chris Weiler
Goffstown, NH