The Narrator
The narrator, presumably the voice of Porter himself, is present in many of his poems. In some of them the narrator addresses a more general audience, while in others he speaks to a specific person.
Mr. Roberts
The principal of the poet's school, who becomes mythologized to the point that he becomes a symbol in Porter's poem "Mr. Roberts."
The Radio Announcer
The announcer and narrator of the poem "Your Attention Please" who announces the beginning of World War III via missile attack. This radio announcer speaks in a very calm, almost banal way.
The Audience
The audience is the both the "you" and the unspoken listener that Porter's narrators address in his poems. As a character, it is able to be interpreted as both the reader and a specific person the narrator is addressing who they may know more intimately.