 Boone's whispers are heard on the Island after his death, talking about Shannon.Some characters to hear the Whispers were Juliet, Jack, Rousseau, Sawyer, Sayid, Hurley, Shannon and Michael on the freighter before he dies.While at first it seems like there are numerous "visions" on "Lost", most of those involving a person who is supposed to be dead are in fact not visions, but are either the spirit of a dead person, or the Man in Black taking on the physical form and memories of a dead person.