|The card's front face||The card's back face|
|Dialogue that is not central to the course of action.|
Chitchat encompasses the forms of NPC Dialogue which are relevant to participate in the game's Acoustic Ecology but which do not carry information relevant for the gameplay. Chitchat can also integrate solutions to represent Unaware NPC and to denounce NPC location (a form of Beacon Locator), but those are different cases of Awareness that we don't intend to reach in this particular card.
On the technique called walla walla: http://www.ruyasonic.com/sfx_walla.htm