The Listeners (1972) - a "fix-up" novel or collection of related novelets by James Gunn. 4 of these came from Galaxy in 1968-1972, the second story came from Magazine of F&SF. "Robert MacDonald- 2058" is original to the 1972 Scribner's hardcover. All pieces are separated by interludes ("Computer Run") - also new to the 1972 hardcover.

Robert MacDonald- 2025 - (original title= "The Listeners")
George Thomas- 2027 - (original title= "The Voices")
William Mitchell- 2028 - (original title= "The Message")
Andrew White- 2028 - (original title= "The Answer")
Robert MacDonald- 2058
The Computer- 2118 - (original title= "The Reply")