If we do not consciously perceive a sound at a time, can we sometimes still later consciously recall it? You all probably know the thought experiment, 'If a tree falls in the forest and no one is their to hear it, does it make a sound?'. But if we take that one step further and ask 'If we are not consciously aware of a sound do we hear it?'. This question as it stands is very broad so let me specify what I mean. 

By consciously aware I mean that we are actively thinking about that sound when it occurs and by hear I mean at some later time, (perhaps with prompting) are you able to recall that there was a sound? 

(Of course the question can be phrased not just concerning hearing but also things like pain, etc).
This question is related to subliminal perception, often studied in vision but sometimes also in hearing. This remains a bit controversial, and that is mostly because of arguments about how ones measures whether something has been perceived or not.

My answer to your main question would be "no", but that is speculation. You use the word "recall", which in memory research generally suggests an explicit, conscious recollection and you would normally only get this if you had consciously perceived something and encoded it the first time round. There are, however, examples of subliminal sounds which are not identified at the first presentation but which nevertheless affect later behaviour (e.g., here).