Separate sounds did not necessarily require their own attention. We can still subtly differentiate numerous different sounds simultaneously but not necessarily be attending to the different sources or channels. But they're still an element to which the complexity of that sound is being processed.

Although I guess that comes back to your first point that it depends on how you define hears, and I may just be defining it a bit different than you. Maybe you're defining it as a sandwich is specifically identified, and I'm defining it as the full total complexity of this sound information regardless of whether specific things are process. But, to be fair to that perspective, sometimes we can think back on a sound we heard recently and reevaluated, drawing attention to the memory trace of different aspects of that sound

The end point limit of a TV types sound system is one that equates to being in the environment. But now that I've said that, I realize the limit of that is in fact the neuronal limit of our processing capacity, cuz the fidelity of real life is infinite. The maximum precision of sound in the universe is whatever the plank sound constant length is, which is effectively infinitely small. Sort of. Almost