>Because you can't even define what consciousness is, let alone objectively test for it.
Exactly. So if we understand "hearing" as something registered by consciousness, then implicitly things that are not conscious cannot "hear".
>reduce the human auditory process
Yes, human auditory process, yes. "Hearing" no. I see that you cleverly switched to the "auditory process" instead of "hearing". moving goal posts, are we?
You are entirely wrong though. You most certainly _can_ reduce the human auditory process to a (bio)mechanical list.
You have unilaterally, arbitrarily, and without justification added consciousness to that list.