This is where they will expose you to deescalating stimuli to get a feel for how or what the minimum is they can do to get a response or reaction out of you. Typically this will occur after you respond to a stimulus that they can walk back. Ie they might fly a helicopter directly overhead and make a loud noise, if you respond, they will do something similar but further away and quieter to see if it changes the way you respond. It’s most obvious with the auditory ques but the principle applies to other types of stimuli as well.