Do you believe it was all of luck that the auditory cortex and the ear components were
evolved altogether simultaneously and very gradually?
No, I think it mutation+selection+fairly well understood aspects of development.
You think it was all poofed by Yahweh-magic from dust all at once, I know.
This naive notion you have of what evolution posits - that these things had to have been all independent events that, by luck alone, happened to have gradually evolved at the same time - is a reflection of your ignorance of evolution, development, neuroscience, etc., not a shortcoming of evolution.
In short, you are operating under one big strawman argument.
The auditory cortex is just cortex that receives axons from the auditory nerves (and other places). There is nothing special about it - it is not nervous tissue that ONLY receives and interprets sound. It is not totally unique compared to other areas of the brain, etc. Your general ignorance of how these things operate, coupled with propaganda from YEC sites, no doubt, has tricked you into believing that there is some grand plan and that everything is specially 'designed' just-so.
But in real life, living bodies are just bags of contingencies, inherited mistakes that worked out in the end, and some "rules" of cellular of biology (such as cells respond differently within concentration gradients of secreted metabolites, etc.).