A truly perfect duologue would be two TV sets tuned in and facing each other.
From the time.com
Alessi, is a longtime collaborator and experienced in duologue himself.
From the nytimes.com
To Kaplan, there is nothing lonelier than two humans involved in a duologue-and nothing more marvelous than two genuinely engaged listeners.
From the time.com
More examples
Dialogue: a conversation between two persons
A part of the script in which the speaking roles are limited to two actors
Duologue are an English electronic music band from London. The band consists of Toby Leeming, Toby Lee, Sebastian Dilleyston, Tim Digby-Bell and Ross Stone.