Place it right after the confusing line in an edit, before your response shot. Follow it with the Ceeday Huh sound for a second confused voice, or lead into it from No No Wait Wait when the mistake needs stopping first.
このサウンドについて
This is a very short reaction clip built around a bewildered wait what response, lasting just over a second. It lands as a quick double-take, turning confusion into a joke instead of a real argument. The feeling is surprised and a little exasperated, like something obvious was missed and only just registered in the moment.