Ud 1.10 Bahiya Sutta http://www.accesstoinsight.org/tipitaka ... .than.html
"Then, Bahiya, you should train yourself thus: In reference to the seen, there will be only the seen. In reference to the heard, only the heard. In reference to the sensed, only the sensed. In reference to the cognized, only the cognized. That is how you should train yourself. When for you there will be only the seen in reference to the seen, only the heard in reference to the heard, only the sensed in reference to the sensed, only the cognized in reference to the cognized, then, Bahiya, there is no you in terms of that. When there is no you in terms of that, there is no you there. When there is no you there, you are neither here nor yonder nor between the two. This, just this, is the end of stress."
My understanding of what I am trying to do on retreats (I follow the Mahasi approach) is, as you say, to "catch" things at the earliest stage, i.e. at "hearing" rather than "hearing a bird".
Of course, this non-conceptual thing is not going to be practical when you are engaged in a task that involves concepts.,.