Brian Ferneyhough uses this term, H&N 27.02.11, to describe listeners who are not quite on top of the listening process, but there is something of a time lag between hearing his music, and some recognition registering in the mind.
Well I would not have thought this was peculiar to his music, but listeners might react in this way to difficult music going back to Brahms and Beethoven.
I'm not sure that this type of analysis is all that helpful. I guess listeners try a variety of techniques to get on top of the music. I have to listen hard - a psychic push, in Brian's words, but perhaps only when I know what I'm listening for?? Other times, it may be best just to let the music flow over the mind.