the expressions that connect to nothing, the words nobody can answer
His face today had assumed various expressions ranging from distended hilarity to scrunched grimace, expressions that seemed unconnected to anything that was going on.
Context
The admissions-room condition seen from outside, months before it arrives: Hal's face already cycling through expressions with no traceable relation to the room (the smile-as-grimace mechanism idling), and his speech already producing no answerable response — the boys note that nobody could say Loach reacted to any of it, so the words simply fall into the tape-work and vanish. The self is broadcasting on a face and a voice that the surrounding people can neither read nor reply to.