What is the author's style in The Sleep of Reason by Antonio Buero Vallejo?

The play has no soliloquies and almost all dialogue is between two people: Ferdinand and Caloverde, Goya and Leocadia, Leocadia and Gumersinda, Duaso and Arrieta, and so on. The dialogue's most unusual feature is that much is signed, Goya being deaf. It is, however, characters speaking to Goya who use it, and rarely Goya himself, since he is deaf but not mute. The other prominent aspect of the dialogue is that the disembodied voices are of two sorts: those of real persons like Mariquita, or of males and females from the paintings. These are heard by Goya and no one els