Being an INTP, I've shared moments with INFPs and Js where something will fall or otherwise make a noise. When it's a faint noise, I see that they will notice it, as will I. However, they will seem keenly disturbed or otherwise jumpy at the occurrence. The same goes with loud crashes or the like, and they will get very shaken up from it. I too get hit by it in a way, because I'm sensitive in picking up very careful and subtle noises. However, I think there's a difference between us somehow, because I am not struck by it in a similar manner. The disturbance will explode in my face and I'll be a bit dazed by the observance, but it will not resonate within me enough to be blown away or shocked by it temporarily.
I suppose what I'm getting at is that IN's (maybe INxP's moreso?) seem to have an ingrained sensitivity to sounds and environmental disturbances. The F, however, seems to connect them to it more and be more affected by it. I think that IN's have a capability to be sensitive to their surroundings moreso than other types, and the F brings out a special edge to it, where they are forcibly involved in all of these subtle happenings. In a more abstract sense, I feel that this sensitivity works in other ways, such as with these types feeling strongly about subtle disturbances in relationships.