Thank goodness they are not "Projecting" their voices on radio!
No, I didn't mean they should do it, but that if they had been taught to (as they would have through necessity a generation or two ago), - I would assume it strengthens the voice up well, and that in itself means there's probably more variety in tone and volume available.
Although I do realise as I type that I've bog all idea of what is taught in drama schools these days and my historical knowledge is based mostly on mid 20th century children's fiction, which may not be an entirely accurate source...