I think they do. A few days ago we were listing to classical music - Rachmaninoff to be precise. i had left the room to go to the kitchen. My husband thought he heard my late father's voice and turned his head to see my father, his own father and a very good friend who passed away some time ago. They were standing and listening to the music! The figures were solid and real. Not wanting to destroy the mood and frighten the figures away he did not call me to see them.
Adrian came to the kitchen to tell me when the music had finished and the apparitions had faded away. He said he had had quite a fright to begin with but then settled down to enjoy not only the music but the company of friends and family.