Mo,

One of Pourparler members described using one of these in a classroom situation. She was a music teacher, as well as a caller, developed strain problems with her vocal folds, so she used one of these to just give her voice a little boost in the classroom. (If you want more info, I can look up her name; I'm at work at the moment. She could say more about the system's benefits & limitations. You could also just post the question there, if you haven't already.)

I've used a karaoke set-up in the classroom (for a similar low-level vocal boost), but I'd think there would be an advantage to having your voice coming from your own location in a classroom (where you might be mixing with dancers), rather than from speakers elsewhere.

~ Becky in Tucson