"Nosotros estamos hablando en la clase."
Translation:We are speaking in class.
So in previous lessons it would say that " Nosotros hablamos" also meant we are speaking. Is this correct?
Yes, it's correct. There are a couple different forms of the present that you can use.
We speak/talk = hablamos (present)
We are speaking/talking = estamos hablando (present continuous)
In the dictionary, both to speak and to talk is translated as hablar, and I use it for both regardless of the audience. The context usually clarifies who is being addressed. Dirigir is also use when speaking of addressing an audience and perhaps is a little more specific. For to say I use decir.